Further modified the enemies.

-Enemies can now be killed by shooting at them or by stomping them.
-Modified the controller so there is a public Jump function that can be
called when stomping enemies.
-Known issues with enemies :
  jumping while running at an enemy makes you stomp on it. (should be
  fixed with knockback)
  Enemies sometimes get stuck in terrain.

  If you have any easy fix to these, feel free to leave me a pm or fix
  it.