Lock keyboard when locking screen. Update UI in final round. Add state machine.
Update logic: put lockscreen in 'state_change' function
Display username when logged on. Fix bugs.
Fix bugs in CCA. UI is not good.
Update UI(table) of front_end.
Merge branch 'master' of https://github.com/Vancy/AuctionDemo

merge in 7 Aug by youyix
Update UI of frontend