*Motivation*

Bump the development version to 2.6.0-SNAPSHOT

* Use classloading to load use code for functions

* fix localrun and add tests

* minor fix

* Improving localrun for functions

* improving impl and adding tests

* add missing modules

Fixes #4456

### Motivation
sometimes, user may use sasl client directly, e.g. use cli command bin/pulsar-client, and if sasl-client not included in, it may meet error of `class not found`

*Motivation*

Currently bookie http server is disabled by default. Setting the http server port
to 8000 and include a vertx http server implementation to prepare enabling http server
on bookie.

*Modifications*

Currently bookkeeper only provides two http server bindings, one is vertx, the other one
is finagle server binding. both are netty based http server. so technically it doesn't
introduce additional dependencies. However if people prefers a jetty implementation,
I can add a jetty binding in bookkeeper.

* Move maven-dependency-plugin in distribution/server/pom.xml

Motivation

maven-dependency-plugin is used to generate a classpath.txt
file with the list of jars for runtime. This is only used
by `bin/pulsar` command and it picks up the dependencies of
the distribution-server module.

There's no need to generate this classpath.txt file for
every module.

* Fixed pom

* [java-11] Compilation fixes

* Runtime fixes

* Fix dependencies for discovery service

* Fixed json mapper provider in new jersey

* Fixed license files

* Added hk2 dep to proxy

* Added hk2 deps to pulsar-client-admin as well

* added missing jar in license file

* More license fixes

### Motivation

Expose metrics in Prometheus regarding the number of log messages printed by each process.

This will add metrics like: 

```
# TYPE log4j2_appender_total counter
log4j2_appender_total{cluster="standalone",level="debug"} 0.0
log4j2_appender_total{cluster="standalone",level="warn"} 1.0
log4j2_appender_total{cluster="standalone",level="trace"} 0.0
log4j2_appender_total{cluster="standalone",level="error"} 0.0
log4j2_appender_total{cluster="standalone",level="fatal"} 0.0
log4j2_appender_total{cluster="standalone",level="info"} 181.0
```

### Motivation

We need to package Pulsar IO connectors as part of the release. 
We provide a new file `apache-pulsar-io-connectors-$VERSION-bin.tar.gz` that contains [NAR](https://medium.com/hashmapinc/nifi-nar-files-explained-14113f7796fd).

In subsequent PR, I'll add the logic to load and use these archives.

Signed-off-by: NSijie Guo <sijie@apache.org>

*Motivation*

There are multiple grpc versions dropped in pulsar binary distribution. It seems that maven
doesn't handle transitive dependencies well on assembly plugin.

```
io.grpc-grpc-all-1.12.0.jar
io.grpc-grpc-auth-1.5.0.jar
io.grpc-grpc-context-1.5.0.jar
io.grpc-grpc-core-1.5.0.jar
io.grpc-grpc-netty-1.5.0.jar
io.grpc-grpc-okhttp-1.5.0.jar
io.grpc-grpc-protobuf-1.5.0.jar
io.grpc-grpc-protobuf-lite-1.5.0.jar
io.grpc-grpc-protobuf-nano-1.5.0.jar
io.grpc-grpc-stub-1.5.0.jar
io.grpc-grpc-testing-1.12.0.jar
```

*Changes*

- Exclude transitive grpc dependencies from functions modules.
- Pin versions for some grpc modules
- Exclude netty dependencies that are already included in `netty-all` module.

*Result*

```
com.amazonaws-aws-java-sdk-core-1.11.297.jar                                  org.apache.commons-commons-lang3-3.4.jar
com.amazonaws-aws-java-sdk-kms-1.11.297.jar                                   org.apache.distributedlog-distributedlog-common-4.7.0.jar
com.amazonaws-aws-java-sdk-s3-1.11.297.jar                                    org.apache.distributedlog-distributedlog-core-4.7.0.jar
com.amazonaws-jmespath-java-1.11.297.jar                                      org.apache.distributedlog-distributedlog-protocol-4.7.0.jar
com.beust-jcommander-1.48.jar                                                 org.apache.httpcomponents-httpclient-4.5.5.jar
com.carrotsearch-hppc-0.7.3.jar                                               org.apache.httpcomponents-httpcore-4.4.9.jar
com.ea.agentloader-ea-agent-loader-1.0.2.jar                                  org.apache.logging.log4j-log4j-api-2.10.0.jar
com.fasterxml.jackson.core-jackson-annotations-2.8.4.jar                      org.apache.logging.log4j-log4j-core-2.10.0.jar
com.fasterxml.jackson.core-jackson-core-2.8.4.jar                             org.apache.logging.log4j-log4j-slf4j-impl-2.10.0.jar
com.fasterxml.jackson.core-jackson-databind-2.8.4.jar                         org.apache.logging.log4j-log4j-web-2.10.0.jar
com.fasterxml.jackson.dataformat-jackson-dataformat-cbor-2.6.7.jar            org.apache.pulsar-managed-ledger-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.dataformat-jackson-dataformat-yaml-2.8.4.jar            org.apache.pulsar-protobuf-shaded-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.datatype-jackson-datatype-joda-2.8.4.jar                org.apache.pulsar-pulsar-broker-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.jaxrs-jackson-jaxrs-base-2.8.4.jar                      org.apache.pulsar-pulsar-broker-common-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.jaxrs-jackson-jaxrs-json-provider-2.8.4.jar             org.apache.pulsar-pulsar-client-admin-original-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.module-jackson-module-jaxb-annotations-2.8.4.jar        org.apache.pulsar-pulsar-client-original-2.1.0-incubating-SNAPSHOT.jar
com.fasterxml.jackson.module-jackson-module-jsonSchema-2.9.0.jar              org.apache.pulsar-pulsar-client-tools-2.1.0-incubating-SNAPSHOT.jar
com.github.ben-manes.caffeine-caffeine-2.3.3.jar                              org.apache.pulsar-pulsar-common-2.1.0-incubating-SNAPSHOT.jar
com.github.zafarkhaja-java-semver-0.9.0.jar                                   org.apache.pulsar-pulsar-discovery-service-2.1.0-incubating-SNAPSHOT.jar
com.google.api.grpc-proto-google-common-protos-0.1.9.jar                      org.apache.pulsar-pulsar-functions-api-2.1.0-incubating-SNAPSHOT.jar
com.google.auth-google-auth-library-credentials-0.4.0.jar                     org.apache.pulsar-pulsar-functions-api-examples-2.1.0-incubating-SNAPSHOT.jar
com.google.code.findbugs-jsr305-3.0.2.jar                                     org.apache.pulsar-pulsar-functions-instance-2.1.0-incubating-SNAPSHOT.jar
com.google.code.gson-gson-2.8.2.jar                                           org.apache.pulsar-pulsar-functions-metrics-2.1.0-incubating-SNAPSHOT.jar
com.google.errorprone-error_prone_annotations-2.1.2.jar                       org.apache.pulsar-pulsar-functions-proto-2.1.0-incubating-SNAPSHOT.jar
com.google.errorprone-javac-9-dev-r3297-1-shaded.jar                          org.apache.pulsar-pulsar-functions-runtime-2.1.0-incubating-SNAPSHOT.jar
com.google.googlejavaformat-google-java-format-1.2.jar                        org.apache.pulsar-pulsar-functions-runtime-all-2.1.0-incubating-SNAPSHOT.jar
com.google.guava-guava-21.0.jar                                               org.apache.pulsar-pulsar-functions-utils-2.1.0-incubating-SNAPSHOT.jar
com.google.instrumentation-instrumentation-api-0.4.3.jar                      org.apache.pulsar-pulsar-functions-worker-2.1.0-incubating-SNAPSHOT.jar
com.google.protobuf-protobuf-java-3.5.1.jar                                   org.apache.pulsar-pulsar-io-core-2.1.0-incubating-SNAPSHOT.jar
com.google.protobuf-protobuf-java-util-3.3.1.jar                              org.apache.pulsar-pulsar-proxy-2.1.0-incubating-SNAPSHOT.jar
com.google.protobuf.nano-protobuf-javanano-3.0.0-alpha-5.jar                  org.apache.pulsar-pulsar-testclient-2.1.0-incubating-SNAPSHOT.jar
com.squareup.okhttp-okhttp-2.5.0.jar                                          org.apache.pulsar-pulsar-websocket-2.1.0-incubating-SNAPSHOT.jar
com.squareup.okio-okio-1.6.0.jar                                              org.apache.pulsar-pulsar-zookeeper-2.1.0-incubating-SNAPSHOT.jar
com.typesafe.netty-netty-reactive-streams-2.0.0.jar                           org.apache.pulsar-pulsar-zookeeper-utils-2.1.0-incubating-SNAPSHOT.jar
com.wordnik-swagger-annotations-1.5.3-M1.jar                                  org.apache.yetus-audience-annotations-0.5.0.jar
com.yahoo.datasketches-memory-0.8.3.jar                                       org.aspectj-aspectjrt-1.8.9.jar
com.yahoo.datasketches-sketches-core-0.8.3.jar                                org.aspectj-aspectjweaver-1.8.9.jar
commons-beanutils-commons-beanutils-1.7.0.jar                                 org.asynchttpclient-async-http-client-2.1.0-alpha26.jar
commons-beanutils-commons-beanutils-core-1.8.0.jar                            org.asynchttpclient-async-http-client-netty-utils-2.1.0-alpha26.jar
commons-cli-commons-cli-1.2.jar                                               org.bouncycastle-bcpkix-jdk15on-1.55.jar
commons-codec-commons-codec-1.10.jar                                          org.bouncycastle-bcprov-jdk15on-1.55.jar
commons-collections-commons-collections-3.2.1.jar                             org.eclipse.jetty-jetty-client-9.3.11.v20160721.jar
commons-configuration-commons-configuration-1.6.jar                           org.eclipse.jetty-jetty-continuation-9.3.11.v20160721.jar
commons-digester-commons-digester-1.8.jar                                     org.eclipse.jetty-jetty-http-9.3.11.v20160721.jar
commons-io-commons-io-2.5.jar                                                 org.eclipse.jetty-jetty-io-9.3.11.v20160721.jar
commons-lang-commons-lang-2.6.jar                                             org.eclipse.jetty-jetty-proxy-9.3.11.v20160721.jar
commons-logging-commons-logging-1.1.1.jar                                     org.eclipse.jetty-jetty-security-9.3.11.v20160721.jar
io.grpc-grpc-all-1.12.0.jar                                                   org.eclipse.jetty-jetty-server-9.3.11.v20160721.jar
io.grpc-grpc-auth-1.12.0.jar                                                  org.eclipse.jetty-jetty-servlet-9.3.11.v20160721.jar
io.grpc-grpc-context-1.12.0.jar                                               org.eclipse.jetty-jetty-servlets-9.3.11.v20160721.jar
io.grpc-grpc-core-1.12.0.jar                                                  org.eclipse.jetty-jetty-util-9.3.11.v20160721.jar
io.grpc-grpc-netty-1.12.0.jar                                                 org.eclipse.jetty.websocket-javax-websocket-client-impl-9.3.11.v20160721.jar
io.grpc-grpc-okhttp-1.12.0.jar                                                org.eclipse.jetty.websocket-websocket-api-9.3.11.v20160721.jar
io.grpc-grpc-protobuf-1.12.0.jar                                              org.eclipse.jetty.websocket-websocket-client-9.3.11.v20160721.jar
io.grpc-grpc-protobuf-lite-1.12.0.jar                                         org.eclipse.jetty.websocket-websocket-common-9.3.11.v20160721.jar
io.grpc-grpc-protobuf-nano-1.12.0.jar                                         org.eclipse.jetty.websocket-websocket-server-9.3.11.v20160721.jar
io.grpc-grpc-stub-1.12.0.jar                                                  org.eclipse.jetty.websocket-websocket-servlet-9.3.11.v20160721.jar
io.grpc-grpc-testing-1.12.0.jar                                               org.glassfish.hk2-hk2-api-2.5.0-b30.jar
io.netty-netty-3.10.1.Final.jar                                               org.glassfish.hk2-hk2-locator-2.5.0-b30.jar
io.netty-netty-all-4.1.22.Final.jar                                           org.glassfish.hk2-hk2-utils-2.5.0-b30.jar
io.netty-netty-tcnative-boringssl-static-2.0.7.Final.jar                      org.glassfish.hk2-osgi-resource-locator-1.0.1.jar
io.opencensus-opencensus-api-0.11.0.jar                                       org.glassfish.hk2.external-aopalliance-repackaged-2.5.0-b30.jar
io.opencensus-opencensus-contrib-grpc-metrics-0.11.0.jar                      org.glassfish.hk2.external-javax.inject-2.5.0-b30.jar
io.prometheus-simpleclient-0.0.23.jar                                         org.glassfish.jersey.bundles.repackaged-jersey-guava-2.25.jar
io.prometheus-simpleclient_common-0.0.23.jar                                  org.glassfish.jersey.containers-jersey-container-servlet-2.25.jar
io.prometheus-simpleclient_hotspot-0.0.23.jar                                 org.glassfish.jersey.containers-jersey-container-servlet-core-2.25.jar
io.prometheus-simpleclient_servlet-0.0.23.jar                                 org.glassfish.jersey.core-jersey-client-2.25.jar
io.swagger-swagger-annotations-1.5.3.jar                                      org.glassfish.jersey.core-jersey-common-2.25.jar
io.swagger-swagger-core-1.5.3.jar                                             org.glassfish.jersey.core-jersey-server-2.25.jar
io.swagger-swagger-models-1.5.3.jar                                           org.glassfish.jersey.ext-jersey-entity-filtering-2.25.jar
javax.annotation-javax.annotation-api-1.2.jar                                 org.glassfish.jersey.media-jersey-media-jaxb-2.25.jar
javax.servlet-javax.servlet-api-3.1.0.jar                                     org.glassfish.jersey.media-jersey-media-json-jackson-2.25.jar
javax.validation-validation-api-1.1.0.Final.jar                               org.glassfish.jersey.media-jersey-media-multipart-2.25.jar
javax.websocket-javax.websocket-api-1.0.jar                                   org.hamcrest-hamcrest-core-1.1.jar
javax.ws.rs-javax.ws.rs-api-2.1.jar                                           org.hdrhistogram-HdrHistogram-2.1.9.jar
joda-time-joda-time-2.8.1.jar                                                 org.inferred-freebuilder-1.12.3.jar
log4j-log4j-1.2.17.jar                                                        org.javassist-javassist-3.21.0-GA.jar
net.java.dev.jna-jna-4.2.0.jar                                                org.jboss-jboss-common-core-2.2.17.GA.jar
net.jodah-typetools-0.5.0.jar                                                 org.jboss-jboss-reflect-2.2.1.SP1.jar
net.jpountz.lz4-lz4-1.3.0.jar                                                 org.jboss.logging-jboss-logging-spi-2.2.0.CR1.jar
org.apache.bookkeeper-bookkeeper-common-4.7.0.jar                             org.jvnet.mimepull-mimepull-1.9.6.jar
org.apache.bookkeeper-bookkeeper-proto-4.7.0.jar                              org.projectlombok-lombok-1.16.20.jar
org.apache.bookkeeper-bookkeeper-server-4.7.0.jar                             org.reactivestreams-reactive-streams-1.0.0.jar
org.apache.bookkeeper-circe-checksum-4.7.0.jar                                org.rocksdb-rocksdbjni-5.8.6.jar
org.apache.bookkeeper-stream-storage-java-client-4.7.0.jar                    org.slf4j-jcl-over-slf4j-1.7.25.jar
org.apache.bookkeeper.http-http-server-4.7.0.jar                              org.slf4j-jul-to-slf4j-1.7.25.jar
org.apache.bookkeeper.stats-bookkeeper-stats-api-4.7.0.jar                    org.slf4j-slf4j-api-1.7.25.jar
org.apache.bookkeeper.stats-prometheus-metrics-provider-4.7.0.jar             org.yaml-snakeyaml-1.15.jar
org.apache.commons-commons-collections4-4.1.jar                               software.amazon.ion-ion-java-1.0.2.jar
```

* Removed internal shading

* Fixed handling of IllegalArgumentException in ZK client wrapper

* Fixed tests with real ZK server

* Move pulsar functions dependency version to root pom and remove duplicated license headers

This addresses some comments in pulsar functions PR #1314

* shade worker

* Fix broken master

* Upgrade the bookkeeper storage client dependency to the official bookkeeper version

This removes the temp dependency in `pulsar-functions-instance`

* set `protobuf2.version` in pulsar-common

* provide a shaded worker

* include worker dependency at broker

* Embeded function worker at broker

* rename 'function worker' to 'functions worker'

* add "--no-functions-worker" for pulsar-client-cpp tests

* Integrate function cli into pulsar-admin cli

- rename `pulsar-client-tools-shaded` to `pulsar-client-admin-shaded-for-functions`, because this module is used by functions only to avoid protobuf conflicts
- move protobuf3 references to Utils, so it won't be referenced out side of pulsar-functions
- integrate function cli into pulsar-admin cli

* Merge pulsar-functions dist package into pulsar binary distribution

* Fix license header issues

* Fixed ZK cache test exectutor configuration.

Fixes #1338

* Switched to BookKeeper-4.7.0-SNAPSHOT + Adjustements

* Added some missing operations to GrowableArrayBlockingQueue

Managed ledger was using UnboundedArrayBlockingQueue from yahoo/bookkeeper branch.

* Removed mock BK classes that are now in BK itself

* Fixed flaky test after refactoring

* Fixed some other tests

* One more flaky test

* Added bk tests dependency to pulsar-client-tools

* Mavenize docker images

Build pulsar docker images with maven. This will make it easier to
pull them in as a base for the maven integration tests.

I didn't touch the publish script, because it has handling for private
registries which I wasn't able to test.

* Fix licenses

* Add log4j2 dependency and configuration

* add yamal configuration

* Add more roll-over-file configuration + log4j2-web module

* Updates headers with ASF source files header

* change license to additional files