change : writing the callback of the contactsFragment
change: finish get the groups name and all the friends name from the
server,and use them to initial the contantsFragment UI
change:i can get the item clicked ,and get the right info of the item
nest step is to build chatroom
change: i can send message and receive message ,but the message need
some correct style
BIG!!!change: i realize that the core of the project is to use service
to run some height task,and send broadcast from service to activity to
change the UI.
now i begin in build friendService
change: the contactsService almost is finished.and the UI is able to 
refresh the nickname or online state at the first time.