Bug 957382: remove r/w locks on buildapi cache; r=catlee
Bug 957385: memcached requires keys be bytestrings; r=catlee
Bug 957384: make buildapi's tests pass; r=bhearsum

There's still quite a lot of work required to get the tests to run, but much
of that is due to the use of Pylons and the way DB access is structured in
Buildapi, neither of which were in scope for this bug.

--HG--
rename : buildapi/lib/test_cacher.py => buildapi/tests/test_cacher.py
Bug 952266: Use Kombu instead of amqplib; r=bhearsum