- added the countdown timer
- When the chat expires, just make the background gray and remove the
onclickhandler. When the user refreshes teh chat list, the server should
delete the chats if they are expired.
`
Merge branch 'master' into hush_chatslist
Merge branch 'master' into vishals

Conflicts:
	Hush/src/com/hush/activities/ChatWindowActivity.java
	Hush/src/com/hush/fragments/ChatListFragment.java