irc commands under config flag and various other

Conflicts:
	binaries/data/config/default.cfg
	binaries/data/mods/public/gui/lobby/lobby.js
Upstream Merge
Tiny cleanup

Conflicts:
	binaries/data/mods/public/gui/lobby/lobby.js
Redesign of IRC command system using much more expandable format.
Add /say command to multiplayer lobby.
New lobby join/leave notification system

Conflicts:
	binaries/data/mods/public/gui/lobby/lobby.js
Small improvements.
Merge branch 'master' of https://github.com/0ad/0ad into lobby
Handle special commands before/instead of sending them.
Merge branch 'lobby' of https://github.com/leper/0ad into lobby
Add GetPresence function and fix irc commands bug
Merge from lobby branch.