change send imageview scale type to centerCrop
modify showvideo by system
add chat sdk lib
fix NPE caused by null filePath
update uidemo
update recieve pic message item
update for picture message
Merge branch 'master' into easemob-dev

Conflicts:
	ChatDemoUI/res/layout/row_sent_picture.xml
update res
support show stranger message
add file
add message web link
Merge branch 'easemob-dev' of https://github.com/easemob/sdkexamples-android into easemob-dev
close strictmode
update demo to show all conversation
remove async send text
chathistory fragment filter empty conversation
show group members size
update ui
modify encrpty img download