* fix deficient code, "/socket.io/" http segment declare
* add agent test and fix expectedData.yaml file
* add listener on tomcat start, work for reduce socket io server start time
change "/socket.io/" operation "http.method", cause get or post will invoke both
* resolve style check error
* change socket io server and client start to health check servlet
* if startClientAndWaitConnect invoke on multi-thread, it will only check client ref, no check connect state, fix it.
* add plugin netty-socketio https://github.com/mrniko/netty-socketio
* delete create exit span interceptor.
* delete create exit span interceptor testcase.
* delete create exit span interceptor testcase.
* add constructor test unit
* change bind on random port in test case
* reverse upstream master whitespace
* resolve build_id param
* delete health check segment test case
* add ContextManager.isActive check before use activeSpan invoke
* remove unnecessary code and blank line
mrproliu