#421 save message delivery status
#419 move OPUser to model
#419 sample move OPUser to model
#421 sdk move OPSession to model
#421 sample move OPSession to model
#419 sdk clean up and consolidate OPSession
#419 sample clean up and consolidate OPSession
#412 guard OPContentProvider and a brillian way of setting up UriMatcher
#429 sample adapt to new database changes
#360 make sure main UI is unclickable while logging in