Moved files
Main menu added
Added Main menu Background image
Added GuiRenderer base abstract class

Used to render any GUI
Added Main menu UI
Parent instantiated nodes to "Mobiles"
minor tweaks
Changed structure of main level
EnemyAI now generate random waves of ennemies
Added UI elements
Spawn area resized
Mobile speed is no capped to MaxSpeed
Added CameraController (singleton)

For future screen shakes ! ;)
EventHorizon now properly calculate Areas sizes.
Menu scene changed

The Menu scene now has EventHorizon controller in it. The levels are
loaded additively.
Globals : removed initializations