remove the temp workaround for sdk.init been called multiple times, since sdk is using a pid file to detect this situation by itself
add send take video
send video length unify with ios
voice download retry
Merge branch 'master' into easemob-dev

Conflicts:
	ChatDemoUI/src/com/easemob/chatuidemo/activity/ChatActivity.java
receiver img msg fail will retry
limit file size