To optimize the function of chat
Merge branch 'Beta1.5' of https://github.com/lejoying/im into Beta1.5

Conflicts:
	androidApp/src/com/open/welinks/MainActivity.java
	androidApp/src/com/open/welinks/controller/ChatController.java
	androidApp/src/com/open/welinks/controller/MainController.java
	androidApp/src/com/open/welinks/view/MessagesSubView.java