Ratchet Explosion
The players can now shoot the ratchet enemies with their rockets and the ratchets will tumble off and explode.
Merge branch 'master' into ratchet_dev

Conflicts:
	JetSetRockets/Assets/Prefabs/Ratchet Thruster.prefab
	JetSetRockets/Assets/Prefabs/Ratchet.prefab
	JetSetRockets/Assets/Scenes/Ratchet.unity
Integrate Changes
Integrates the ratchet explosion changes with the changes to its appearance.