Try to draw a line bewteen bases.
Problem with superposition of elements.
UnitSprite : add a unitSprite when you send a unit from a base to an
other.
Need to fix : the first position of the unit, and his movment.
fix #13
UnitSprite : move units !
Problem : they never stop^^
Refactoring : add comments.
Refactoring : the dispatcher contains the main loop.
It's a better way to separate clearly the engine and the renderer.