also deleted unnecessary quality settings.

Instead of acting as a bullet power up it now immediately destroys a
trap on pickup. The trap closest to any player (excluding the player
that picked up the destroyer) is destroyed.

This fixes #4

bugfix: missing bullet prefabs on player. also set heal powerup prefab to trigger and changed bullet speed.

Conflicts:
	Assets/Resources/Levels.xml

--> ground prefab needs to be fixed!
Scale: 22, 0.2, 1
sprite: square_anchorLowerLeft.png
BoxCollider: Offset 0.5 0.5,     Size: 1 1