Fix issue that skywalking-agent.jar include the google class  and exclude the proto files inside protobuf-java

Finish almost all codes about ignore, sample and analytic trace mechanism. Left analytic trace only for collector.

Add parts of ignore mechanism, and this is part of new sampling mechanism. All of these are providing higher performance.

1. Remove the “apm-trace” module, isolate the trace structure between agent and collector for considering performance.
2. Change the head name.
3. Provide potienal mechanism for ignore trace with certain suffix.

Fix the wrong key of poolMap

This reverts commit 19f2a561.

add test case for okhttp interceptor

* Add mechanism to disable any or all plugins, Relate: #186