* 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
* Support for overriding config with agent options
* Test the separator of options
* support quotes in agent options
* revert imports change
* add more tests
* clear properties after each test
* add document
* fix code style
* Replace v5 changes by a link to 5.x branch. New v6 changelog.
* Finish query doc and fix a missing field in alarm doc.
* Add link to official oal in alarm doc.
* Fix words.
* Fix some doc
* Update README.md
* Update README.md
* Update README.md
* Update README.md