Added Fog wrapper class for OpenStack access.

@Fryguy @chessbyte please review.

The Wrapper class implements a single connection object that provides
access to all OpenStack services for a given connection.
It performs higher-level functions and facilitates service and tenant access.

Its intended use is by fleecing and inventory collection clients, implementing
patterns common to both. These clients won't be modified until after current
outstanding pull requests are merged.