1165355 - Add a sanitize_checksum_type function.

https://bugzilla.redhat.com/show_bug.cgi?id=1165355
Merge branch '2.4-testing' into 2.4-dev
Merge branch '2.4-dev' into 2.5-testing
Merge branch '2.5-testing' into 2.6-dev
Merge branch '2.6-dev'
Automatic commit of package [pulp] release [2.4.4-0.1.beta].
Automatic commit of package [pulp-nodes] release [2.4.4-0.1.beta].
Merge branch '2.4-testing' into 2.4-dev
Merge branch '2.4-dev' into 2.5-testing

Conflicts:
	nodes/pulp-nodes.spec
	pulp.spec
	rel-eng/packages/pulp
	rel-eng/packages/pulp-nodes
Merge branch '2.5-testing' into 2.6-dev

Conflicts:
	pulp.spec
Remove client unittest dependency on NamedTuple
Merge branch '2.6-dev'
Automatic commit of package [pulp] release [2.5.1-0.1.beta].
Automatic commit of package [pulp-nodes] release [2.5.1-0.1.beta].
Merge remote-tracking branch 'origin/2.5-testing' into 2.6-dev

Conflicts:
	nodes/pulp-nodes.spec
	pulp.spec
	rel-eng/packages/pulp
	rel-eng/packages/pulp-nodes
Merge remote-tracking branch 'origin/2.6-dev'
Merge branch 'jenkins-namedtuple' into 2.5-testing
Merge branch '2.5-testing' into 2.6-dev
Merge branch '2.6-dev'
PEP-8 server.managers.repo.unit_association_query.

Also PEP-8 its tests. It turns out that we skip several of the tests in
this module, and that they do no pass if they are run. They have weak to
no assertions, so perhaps it would be best if we removed them in the
future.