Added 4 expressions in OAL syntax: >, <, >=, <=.

Merge remote-tracking branch 'origin/qualified-spring-mvc-endpoints' into qualified-spring-mvc-endpoints

* Rename ALarmSupported to WithMetadata

* Finish the base of exporter.

* Fix class comment.

Async core APIs in java agent

* Update powered-by.md

Change order

Update apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java

Fix isInAsyncMode never be set.
Co-Authored-By: wu-sheng <wu.sheng@foxmail.com>

Remove the version setting in dependencies.
Remove the scala compiler version property.

* bugfix: fix bug when spaces in agent path. resolve #1219

* fix code style

* fix code style

* fix issue #2258

* fix #2097 #1947

* remove Description and date tag

* split the diferent version to different plugins

* resolve conflict

* record all ips on multiple host mode of mysqlconnector-5x

* fix jdk 6.x

* optimise the code

* optimise code

* modify class name

* fix #2097 #1947

* i do not think it is a good idea to move the Instrumentation to mysql-common,the better way is extract a public method to return the InteceptorPionts in mysql-common

* fix #2097 #1947

* remove witnessClasses of subclasses

* Submit custom enhancement kernel code for the first time.

* Submit the code again.

* Optimize ClassUtil code.

* Submit custom enhancement plugin code for the first time.

* To fix CI issue.

* To fix CI header Tmp issue

* To fix CI Tmp header issue

* Customize plugin code submission

* Add md file.

* Fix some bug.

* Fix ci issue

* Fix md desc

* Fix unapproved license

* Fix bug

* Fix collection bug.

* Fix java8 pair ref issue

* Fix CI issue.

* Add more detail for expression.

* Fix review issue

* Fix review issue 2

* Fix review code issue 2

* Fix md issue

* Fix bug and op desc md.

* Update customize-enhance-trace.md

* Update customize-enhance-trace.md

* FIx code review issue.

* Make k8s-Coordinator back in role mode.

* Start query API server after the core started.

* Do lock when port has been intialized.

* Rename service.

* Fix text cases.

* Declare ConfigService.class in core module.

* Implement in an easier way.

* Envoy print whole metric, now in debug.

* Forcedly fix envoy timestamp issue.