* feat:Active System.env Config In Both Collector And agent.config.
1、moving related codes into apm-util module.
2、update Setting-override.md about how to use.
* resolve docs.
* typo
* finish test case.
* Update README.md
* 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.
* Manually trigger agent registration and write registration status to file
* Delete unused variables
* Code optimization, encapsulating some methods
* add clear DataCarrier function
* revert SkyWalkingAgent
* Optimize code and logic, including updating applicatin_id in unRegisterOperationNames
* Server end metadata loss notification
* Server end metadata loss notification
* fix file stream close and other problem
* revert to old
* fix some bug
Signed-off-by: Liu-XinYuan <879928098@qq.com>
* fix some bugs in agent reset
* add close inputStream and fileChannel and fix some bug
* fixed some bugs
* Provide document for TLS
* Provide direct uplink doc.
* Add namespace document.
* Provide token auth doc.
* Provide setting override document.
* Fix two typo.
* Fix more typos.