Make auth_token return a V2 Catalog

As there is no way to distinguish a v2 or v3 catalog from the headers
provided to an application we will for the meantime always return a v2
catalog. This should not cause any issues as the full token data is not
provided to the service so there is no-one that will get caught out by a
v2/v3 mix, and anyone that is already supporting the v3 catalog format
will have to support the v2 catalog format as well so it will continue
to work.

Change-Id: Ic9b38e0ba4682b47ae295bd3f89bac59ef7437cf
Closes-Bug: #1302970
Move auth_token cache pool tests out of NoMemcache

There were cache pool tests in NoMemcacheAuthToken. Since this class
un-imports memcache, setting the memcached_servers option would just
be ignored anyways.

The tests were moved into a separate class and changed to not set
memcached_servers. The behavior should be the same.

Also, there was a cache pool test in CommonAuthTokenMiddlewareTest
that fit better in this new class.

Change-Id: Icfce7398f2a29753200c2010bba58924980622c0
replace string format arguments with function parameters

There are files containing string format arguments inside
logging messages. Using logging function parameters should
be preferred.

Change-Id: Ibd9def4cf111d5dcf15dff64f85a723214a3c14e
Closes-Bug: #1320930
Merge "Make auth_token return a V2 Catalog"
Merge "replace string format arguments with function parameters"
Merge "Move auth_token cache pool tests out of NoMemcache"