Allow clients to determine the difference between create or update on PUT

PUT allows an object to be created (http 201).  This allows REST code to
indicate an object has been created and clients to react to it.

Plan on using this for some oauth / user level interactions in the future.
Yeah I realized after I got home that you did this because it has to go through the channel. I guess I would prefer to change the type of the thing we put through the channel (to a struct of runtime.Object, suggested return code?), even though that's pretty awful, too. It seems less hacky than pretending to be an api object.