add new user

* Register start up.

* Service inventory register test success.

Remove collector.servers and collector.direct_servers, and add collector.backend_service setting. cc @ascrutae

@peng-yongsheng Found you have two `endpoint` concepts in different package. I have rename the one in register, the new is `endpointInventory*`. Because the register and meta data of the cluster should be named inventory.

* Refactor register and analysis modules.

* Fixed the startup error.

* 优化代码结构,减少不必要的计算,节省计算资源

* 优化代码结构,减少不必要的计算,节省计算资源

* Use annotation to instead of definition file.

Refactor documents. Delete all backend documents, cc @peng-yongsheng , considering backend refactored, then the documents should rebuild manually.

* Use elasticsearch's document version to implement a lock for register source id.

* Return false when could not lock the document.