Backport of multiple bug fixes.

This contains multiple bug fixes that could not be cherry-picked
individually due to a backward incompatible change in novaclient.
This contains the following commits:

 - 3323632 One place missed
 - de42ea8 Removed use of older-version response status checking
           from nova + mgm code, replaced with requests-bas
 - 739413f Re-enable pyflakes.
 - 8316e49 Fix tests directory for Debian packaging
 - cda6f89 Fixed minor typo in pool_mgm --help output

Change-Id: I41fadb7f908250262fe082ca39c47f409750909e