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

This reverts commit c52686f8.

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

2. Change the http servlet worker from local asynchronous call to local synchronous call.

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.

This reverts commit 04041ebd.

* add feign default http plugin
add test case for feign default http interceptor

* move feign and okhttp plugins to the parent moudle

Remove out-of-date readme file.

add test case for okhttp interceptor

* add plugins for resin-3.x and resin-4.x 

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