[OSX] Allow connecting to multiple servers

[mixflame]

Invent a way to reopen server list without exiting

Cause ServerList to only create new windows when connecting

Change exit to disconnect all, re-enable X button on particular server, but make it cause logoff

Enjoy multiple server GlobalChat !

[mixflame]

Make a new @chat_window

Make a new @gcc for it

Remove global usage

Change Cmd+Q design to quit again

Make ServerList showable whenever without logging off

Any logins from ServerList just instantiate a new GCC and a new Window with that

Make individual window close buttons SIGNOFF

[mixflame]

Investigate NSWindowController usage. Seperate the XIBs.

This will allow creating a new window with it's own GCC.

Just need to figure how to pass the vars to it without globals.

NO Globals ! :)