Fix issues with test_wsgi.py and Storage Policies

Discovered some tests that were coupling the code under test with the
storage policies configured in /etc/swift/swift.conf.  There was some
tests that created fake rings in their tempdirs, but didn't reset or
patch the POLICIES global.  So if your local config needed more rings
that the fake's were setting up (just 2) the tests would puke when they
loaded up an app that looked for rings.  I think this probably started
happening when we added eager object ring loading back into the proxy.

 * two TestCases in test_wsgi were missing @patch_policies
 * fixed issue with patch_policies that could cause state to bleed
   between tests
 * patch_policies' legacy and default collections get a FakeRing by
   default

 * drive-by cleanup for test_loadapp_proxy() ring serialized path
   handling
 * drive-by cleanup for test_internal_client that was doing basically
   the same thing as test_wsgi

Change-Id: Ia706000ba961ed24f2c22b81041e53a0c3f302fc
Merge "Fix issues with test_wsgi.py and Storage Policies"