fix issue restemplate plugin don’t works fine

fix issue that controller cannot find the request mapping

Make agent gRPC to be a collector module.
Make agent jetty to be a collector module.
Make agent stream to be a collector module.

Feature/stream jetty

Trace segment compute by http json stream test success.

Appand modules: apm-collector-baseline and apm-collector-baseline-computing for jd contributor team.

Provide new collector modelization core and graph streaming core

Merge branch 'feature/collector-modelization' of https://github.com/OpenSkywalking/skywalking into feature/collector-modelization

Merge branch 'feature/collector-modelization' of https://github.com/OpenSkywalking/skywalking into feature/collector-modelization

Add Span amount control mechanism, also memory limit mechanism

* Update architecture graph.
* Update REAMDME.