renamed global scale to current scale
added mouse wheel check
scale is now controlled by mouse wheel
background now zoomed correctly
switched zooming
grey outside area now correct
added maximum for zooming out
added maximum zoom
Merge branch 'develop' into feature/issue/#43

Conflicts:
	src/engine/Enemy.java
	src/engine/graphics/BackgroundTiles.java
	src/engine/graphics/PathTiler.java
	src/engine/projectiles/Projectile.java
	src/towerDefense/Gameplay.java
	src/towerDefense/towers/BombTower.java
	src/towerDefense/towers/RocketFastTower.java
	src/towerDefense/towers/RocketTower.java
	src/towerDefense/towers/ShootingTower.java
fixed moving camera when zoomed in
moving camera now better
start scale better
tower shadow position now correct
better background when zooming
better background on big maps
cleanup
better enemy position when moving the camera
better tower place griid when moving camera
bomb tower position corrected
better position of enemy radius debug