Make Ethan as more or less a speed bump in the game

The existing NPC served a valuable purpose to the game story, but Ethan
had no real justification. This allowed him to be used to test the
concept from
http://www.hernanzaldivar.com/2013/11/unity3d-kill-character-and-make-hi
m-die.html about animator to ragdoll using some new research on how to
operate colliders.