Better handling of floating IPs, pep8/pyflakes fixes

Ok! All in one, nice, clean changeset!

HP Cloud doesn't give one the ability (404) to obtain a network list and for me, I found that it took reading through salt source, openstack driver code to finally figure out how to get a cloud provider and profile to work properly particularly due to how with Havana, one has to manually assign a floating IP to an instance to access it. So, what I've added here is the functionality that if the floating ip pool is not defined, it will try to obtain a list of floating IPs anyway and use that. Also updated the document a bit. Lastly, I made the code pep8/pyflake copastetic :)