* Move submodule plugin.

* Always auto-submodule

* [maven-release-plugin] prepare release v6.1.0

* [maven-release-plugin] prepare for next development iteration

* Change keys location.

* Fix #2546

* Change the stackdepth type

* Fix bug

* Fix CI failed

Update all "incubator-skywalking" to "skywalking" ,"incubator-servicecomb-java-chassis" to "servicecomb-java-chassis" correctly, and ".gitmodules" will update at #2531 (#2548)

* [maven-release-plugin] prepare release v6.0.0-GA

* [maven-release-plugin] prepare for next development iteration

* Support webflux and spring mvc 5 plugin

* Change instrumentation

* Change instrumentation

* fix check style

* Add support 2.1.x instrumentation

* Fix the components of Spring resttemplate is incorrect

* Fix check style

* Fix the version is incorrect

* Fix checkstyle

* Update new protocol

* Support new protocol at agent side.

* Fix test case.

* Make backend supports new trace protocol

* Fix tests.

* Make all new services available in gRPC.

* Fix bugs.

* Finish new document for v2 trace protocol.

* Fix wrong version requirement of zk

* Fix trace query bug.

* Find a client side dictionary bug.

* Fix register bugs.

* Fix break doc links.

* Lock oracle and resin plugins version.

* Move resin and oracle plugin to openskywalking

* Restore submodule active.

* Add another submodule active command.

* Remove the wrong test cases in release and fix some doc issues.

* [maven-release-plugin] prepare release v6.0.0-alpha

* [maven-release-plugin] prepare for next development iteration

* Fix some doc

* Fix bug stop stopSpan when not createSpan

* Fix bug stop stopSpan when not createSpan

* Fix RuntimeContext cannot store anything when the trace is not create

* Add RuntimecontextSnapshot and remove debug info

* Change version 

* spring mvc plugin auto add '/' if necessary

* spring aop patch #1114

* more strict check