Caffeine license,  Apache 2.0, no NOTICE file in repository which is https://github.com/ben-manes/caffeine. (#1046)

* 1. Add the performance collection point.
2. Report formatter.

#1032

* Add a new cache implementation by caffeine.

#1032

* Performance optimization:
Make all the loggers class variable to have the static modifier.

* Time stamp format to time bucket performance optimization.

#1032

* 1. Add the performance collection point.
2. Report formatter.

#1032

* Add a new cache implementation by caffeine.

#1032

* Performance optimization:
Make all the loggers class variable to have the static modifier.

* 1. Add the performance collection point.
2. Report formatter.

#1032

* Add a new cache implementation by caffeine.

#1032

2. Report formatter.

#1032

* Update pom.xml

Add developer email address.

* Update pom.xml

* Update pom.xml

* Delete pom.xml.versionsBackup

* Delete pom.xml.versionsBackup

* Update pom.xml

* Delete pom.xml.versionsBackup

* Update pom.xml

* avoid "by zero" exception when all request are error

* update pr about "by zero" exception

* update pr about "by zero" exception add 3 file change

* update pr about "by zero" exception add 1 file change

* update pr about "by zero" exception to solution 1

* Enable the build of ServiceComb Java Chassis

* Updated the Supported list

* Update release docs.

* Adjust doc.

* Fix a missing wrong url.

* Because of key issue, system env override can't be supported.

* Override value only in supported types. Int, String, Long, Boolean.

* Add documents about vote result and announce.

* Update description about SkyWalking in mail templetes.

* Remove the -1 allowed rule. Even it is a right rule, but we don't encourage people do that.

* Add a svn move example.

* Provide document for TLS

* Provide direct uplink doc.

* Add namespace document.

* Provide token auth doc.

* Provide setting override document.

* Fix two typo.

* Fix more typos.

#1009

* Collector instrument agent.

* Make the agent.jar output to the /agent folder in collector package.

* Try to add metric annotation.

* Change the instrument ways.

* Reformat.

* Finish the agent codes. Wait for @peng-yongsheng 's metric requirements.

* Debug new instrument.

* Fix a detect bug.

* Finish the instrument

* Fix compile issue.

#1007

* Add client side token.

* Fix ci.

* Fix most codes of token auth at both sides.

* Add settings in config files.

* Make auth interceptor doesn't throw expcetion.

* Update AuthenticationSimpleChecker.java

* Update AuthenticationActivator.java

* Revert "Update AuthenticationActivator.java"

This reverts commit 0935f18fd6802ab84c12e0609c21ef753ff51be3.

* Merge branch 'feature/token-auth' of https://github.com/apache/incubator-skywalking into feature/token-auth

# Conflicts:
#	apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/AuthenticationSimpleChecker.java

* Fix Auhentication token works incorrect (#1001)

* Fix Auhentication token works incorrect

* Change way to build GRPC Channel

* Response an empty header when auth fails.

#998

Fixed #999

* Fix link to proto files

* Fix proto path.

* Support setting override through system.properties and envs.

* Remove test case.

* Upload more dependencies.

* Add all UI licenses to license file.

* fix ui

* Update How-to-release.md

* Update How-to-release.md

Fix IPMC checks for releasing.

* Support direct server setting in agent.

* Fix format.

* Add direct_servers check (#981)

* Finish the prototype of TLS of gRPC between agent and server.

* Fix for rat check.

* Update GRPCChannelManager.java

* Update AgentModuleGRPCProvider.java

* Upgrade netty version (#971)

* Make sure end user can't start gRPC server with and without SSL in the same port.

* Proposal the code structure for table name prefix. Related to #932

* Fix style check.

* Keep ESDao table name in control.

* Finish all codes about ES namespace feature.

* fix #939

fix #939

* fixcheckstyle

* add npm install error tips.

tell people use taobao's npm source.

* Update How-to-build-CN.md