Added radius_ variable to Player for collision detection with Enemies. Added maxhealth_ with appropriate getters and setters. SetMaxHealth also sets health to that integer. Adjusted constructors to fit this.
Merge branch 'Enemies' of https://github.com/gametechnology/psi-2013 into Enemies

Conflicts:
	source/Game/Enemy.cpp
	source/Game/EnemyAsteroid.cpp
	source/Game/EnemyAsteroid.h
	source/Game/EnemyDrone.cpp
	source/Game/EnemyFighter.cpp