Add displaying of radial menu when clicking on base
Add Radial Menu on tower and base to choose how many agents we send
fix #25
Merge branch 'master' of https://github.com/cchampet/Java_nanowars.git

Conflicts:
	src/dispatcher/Dispatcher.java
	src/renderer/MapRenderer.java
	src/renderer/Renderer.java
	src/renderer/UIRenderer.java
Update Tower leveling
fix negative agents number bug
add a better level exp scale
add a unit send back when the tower is full