removed hard coded tile size and added it to constructors
made towers block tiles once placed
Merge branch 'towerdefense2.0' of https://github.com/duke-compsci308-spring2013/vooga into towerdefense2.0

Conflicts:
	src/vooga/towerdefense/controller/Controller.java
	src/vooga/towerdefense/factories/elementfactories/GameElementFactory.java
Merge branch 'towerdefense2.0' of https://github.com/duke-compsci308-spring2013/vooga into towerdefense2.0

Conflicts:
	src/vooga/towerdefense/controller/Controller.java
	src/vooga/towerdefense/gameeditor/gameloader/GameLoader.java