#2 - Placing buildings on a tile

Added functionality to place buildings.

Buildings should have component buildable.
Builder script should be assigned to Manager.
Assign all buildings you want to build in Builder script.
Builder script should be unique on a scene (It is a singleton).
Use "z" to choose previous building, use "x" to choose next building. By default 0.
On each tile should be component "BuildBase".

SirMrMaffin / CityBuilderGame