Update cloudfront model to 2013-09-27

Part of this change was reworking the model translations to perform the operation renames before applying any operation enhancements like pagination configs or extra operation attributes.  This lets us refer to the operations by their transformed names instead of their name in the model.

This was specifically for cloudfront, where we strip off the API version
from the operation names, but want to apply the same pagination configs
defined in cloudfront.extra.json.  Otherwise we have to update the
pagination configs every time we update the model.