* 🎉 PHP agent

* Update powered-by.md

Change user list order

* Refactor service instance inventory to properties based entity.

* Fix a bug and refactor properties update.

* support overview-cn.md translation

* update overview-cn.md translation

* update fix error statement problem

* update fix error statement

* plugin support redisson

* Add properties for service inventory

* Fix code bugs

* Provide develop doc for inventory extension.

Add 5 new users based on #443

* remove duplicate config in docker.

* Revert "remove duplicate config in docker."

This reverts commit eb774035

* update content.

* Change a label name for  sw instance to avoid confict.

* Fix a wrong metric name.

* Fix too many counter instances.

* Set uptime to second.

* Fix format.

* Fix format

* Remove two unnecessary counter.

* Provide grafana dashboard settings and remove unnecessary metric.

* Provide a simple UI brief doc. Fix #2137

* Finish the basic codes of telemetry.

* Add many telemetry in oap.

* Fix a test case.

* Finish all telemetry metric.

* Fix format.

* Make telemetry works.

* Support JVM metrics.

* Add doc for telemetry.

* Fix typo.

* Fix #2135

* Finish the APIs of telemetry module.

* Add prometheus license.

* Active default telemetry provider.

* add ojdbc component id

* Support Gson plugin

* Update submodule skywalking-ui

* Update submodule skywalking ui

* Update README.md

* Update README.md

* Fix doc.

* Fix typo

* fix incorrect version in apm-checkstyle.

* remove SNAPSHOT in checkstyle module.

* fix classloader dead lock in jdk7+

* support springcloud fegin 2.x

* update pom

* fix checkstyle

* fix checkstyle

* Update pom.xml

* cn doc

* cn doc

* cn doc

* cn doc

* cn doc

* delete cn default readme

* Fix application cannot start when the dubbo interface with @RequestMapping

* Refactor register API for making integration easier.

* Fix wrong refactor.

* Update powered-by.md

* Update powered-by.md

I change the order. This list should be in alphabeta order.