Add unit tests for glance.api.cached_images module

Add positive unit tests for methods:
* get_chached_images
* delete_cached_images
* get_queued_images
* queue_image
* delete_queued_image

Fixes: bug #1155188
Change-Id: I3fa6dc28a72e8c6e8402911931fb37e18cba7ea0
Verify SSL certificates at boot time

When Glance is configured to run with SSL this patch will check
that the certificate and key exist, are readable, and match each
other at boot time.  If any of the above conditions fail an friendly
error message is logged directing the operator at a solution.
Previously the keys were not checked until a client connected.

fixes bug: 1160529

Change-Id: I16975608f9ae40ac5b84b3caa52ed5f8e22f296e
Fix the deletion of a pending_delete image.

Return '403 - Forbidden' when trying to delete
a 'pending_delete' image, and does not change
its status.

Change-Id: Id5b8b31c19d0f9da8aba66b06d1b966e9c33a363
Fixes: bug #1163020
Fix Qpid test cases

The Qpid notification test cases do not currently pass.
By default they are skipped because qpid is not part of
test-requires, so it isn't automatically installed.  This fix
updates the test cases to work correctly, but does not add
qpid to test-requires because I'm unsure what impacts that
might have on other platforms.

This is part of the fix for bug 1164681

Change-Id: I40757b5de99559b4ff090e0d249f8624c2e2be10
Merge "Fix the deletion of a pending_delete image."
Merge "Fix Qpid test cases"
Merge "Add unit tests for glance.api.cached_images module"
Merge "Verify SSL certificates at boot time"