* Move availability_zone docs to each OpenStack module
This argument is in the central list for hysterical raisins (mostly me
being a doofus) but is used in almost none of them. Document it
explicitly in each module to stop the confusion.
* Fix two docs formatting bugs
* Update validate-modules
* Validates ANSIBLE_METADATA
* Ensures imports happen after documentation vars
* Some pep8 cleanup
* Clean up some left over unneeded code
* Update modules for new module guidelines and validate-modules checks
* Update imports for ec2_vpc_route_table and ec2_vpc_nat_gateway
Depending on the OpenStack installation it may be quicker to create a volume from an existing volume (copy-on-write) compared to from a snapshot (allocating a completely new volume).
This adds a new `volume_src` parameter to the `os_module` which accepts a volume id or name.
The exception message, when shade fails, will contain much more
specific information about the failure if the exception is treated
as a string. The 'message' attribute alone is usually not helpful.
