Trivial: Remove unnecessary for loop in Atmos signing
Fix OpenStack Nova SecurityGroupExtension based on live tests

So there were a few problems, but the core ugly one is that what you
pass in for creating a rule allowing groups' access is not the same
thing you get back from a group with such a rule, which makes mapping
between the arguments and the output insanely painful. So now, well,
we do some insanely painful stuff.
JCLOUDS-334. Return correct status while creating containers in Swift.

BlobStore.createContainerInLocation is supposed to return True if the
container was newly created and False if the container already
existed. This commit makes that happen for Swift blobstores.