把displayname函数名改为display，在UserReader增加newDisplay
Merge branch 'dev-iron' of https://github.com/FeverTeam/LivePPT-Play2 into dev-iron

Conflicts:
	LivePPT-2/app/com/liveppt/services/UserService.java
	LivePPT-2/app/com/liveppt/services/impl/UserServiceImpl.java