Fixes bug 996922
This commit adds a user_crud module that can be used in the public wsgi
pipeline, currently the only operation included allows a user to update
their own password.
In order to change their password a user should make a HTTP PATCH to
/v2.0/OS-KSCRUD/users/<userid>
with the json data fomated like this
{"user": {"password": "DCBA", "original_password": "ABCD"}}
in addition to changing the users password, all current tokens
will be cleared (for token backends that support listing) and
a new token id will be returned.
Change-Id: I0cbdafbb29a5b6531ad192f240efb9379f0efd2d
4ab47ad224