notification (work with production & dev)
https://github.com/windylee/tz/issues/47
add user_id to registernotification
make notification push for new message
change notification format
https://github.com/windylee/tz/issues/13
documentation in code
https://github.com/windylee/tz/issues/49
add updatemessage
add first_name, picture to notificaiton
..
notificaiton: reduce size
...
Phong modified
change 'notification' -> 'apns_notification'
test gcm
add gcm notification for android
add conversation_id
adjust new message count in conversation
...