Revert "commenting out failing test due to issue https://code.google.com/p/googleappengine/issues/detail?id=10493"

This reverts commit dc99e3e8c9c8ad28baa1fe733d955808ff8c26fb.
Revert "Revert "created an internal goon.timeout() function since appengine.Timeout(context,duration) didn't work in the development environment""

This reverts commit 31cbc2aadb6e7c664e5e6b90092f6111872a67db.
Using build tags in order to test timeout related code changes to goon