* Provide consul cluster plugin.
* Change log and application config file.
* Add consul's config item into the docker's application.yml.
* Fixed bug.
* Add consul description into readme.
* Add okhttp component license.
* 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