recreate views when language is changed
loads private chat via user list and private chat list
fixed udp close socket on exit
updated ui to show username
Merge branch 'master' of https://github.com/mtleung/iems5722.git

Conflicts:
	ChatApp/src/com/iems5722/chatapp/gui/Activity_PrivateChat.java
	ChatApp/src/com/iems5722/chatapp/gui/Activity_TabHandler.java
	ChatApp/src/com/iems5722/chatapp/network/PeerFileReceiver.java
	ChatApp/src/com/iems5722/chatapp/network/PeerFileSender.java