Add followed operations:
	- Subscribe to a channel
	- Open a discussion frame when subscribe to channel
	- Unsubscribe when leave channel
	- Hidde frame when close but not leave
	- Information when client connect on server
	- Information when client disconnect from server
	- Information when client subscribe on channel in main and discussion
side
	- Information when client unsubscribe to channel only in main side for
now
	- Create channel
	- Subscribe to a channel when created and open discussion frame
	- Remove channel and inform all user just before close their discussion
frame
	- Remove discussion owner when owner leave (need to fix with survey to
get new owner)
	- Resizing main frame resizes subject panel
	- Some others things