Network: Add message PlayerJoined
GameClient: Handle game start
GameHost: Handle game starting
Network: Run graphics tasks on the graphics thread
gui : host lan screen tweaking
Merge remote-tracking branch 'origin/raie-zo' into gui

Conflicts:
	src/fr/miage/atlantis/gui/controllers/GuiController.java
	src/fr/miage/atlantis/logic/GameLogic.java
	src/fr/miage/atlantis/network/GameClient.java
	src/fr/miage/atlantis/network/GameHost.java
	src/fr/miage/atlantis/network/NetworkObserverProxy.java
	src/fr/miage/atlantis/network/messages/MessagePlayerJoined.java
gui : adding some comments
Merge remote-tracking branch 'origin/gui' into raie-zo

Conflicts:
	src/fr/miage/atlantis/logic/GameLogic.java
	src/fr/miage/atlantis/network/GameClient.java