Allow a configurable set of TempURL methods

Folks have actually been asking for this. I think they're sending a
DELETE TempURL to someone way ahead of time and the someone issues it
when they're ready. Honestly, I'm not entirely sure of the use case,
but having the set of methods configurable wouldn't hurt.

Change-Id: Ibdb48f8a72077b045eeedddfae4c0a1f56098d7a
Merge "Allow a configurable set of TempURL methods"