Uses six.iteritems for Python3 compat

Change-Id: I968c349919517bf02b331a8620b17e1789c30dc1
Implements: bp keystone-py3kcompat
Use WebOb directly for locale testing

In the convert to Pecan we can't overload the Request type like we do
currently. At the moment we add only one method to request about
determining a locale which can be easily converted to a standalone
function.

Change-Id: I55de36d5ebc35ae868c9048dd4972df1634e2ee4
Blueprint: keystone-pecan
Merge "Use WebOb directly for locale testing"
Merge "Uses six.iteritems for Python3 compat"