Unify broadcast transunit updated event

- it appears we only care if the update type is from editor save or not. So the commit 0111ad8 is to consolidate it
- separate comment update event from transunit updated event
- concurrent edit warning only compares session id now. I think if the session id is the same means it's same user on different tab. They know what they are doing.
- hibernate entity listener to capture all update and broadcast the events