Changes to the metadata format were approved here:
https://github.com/ansible/proposals/issues/54
* Update documentation to the new metadata format
* Changes to metadata-tool to account for new metadata
* Add GPL license header
* Add upgrade subcommand to upgrade metadata version
* Change default metadata to the new format
* Fix exclusion of non-modules from the metadata report
* Fix ansible-doc for new module metadata
* Exclude metadata version from ansible-doc output
* Fix website docs generation for the new metadata
* Update metadata schema in valiate-modules test
* Update the metadata in all modules to the new version
* 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
* Added support for a gce_snapshot module for managing snapshots in the Google Cloud Platform
* Fixed using sys.exit in favor of fail_json. Followed the pattern in gce_pd
* Fixed using sys.exit in favor of fail_json. Followed the pattern in gce_pd
* Fixed an issue when dealing with multiple disks. Added a bit more documentation explaining the disks argument
* Corrected a typo in the multi-disk snapshot example
* Updated module to return list of changed snapshots instead of just a message. Added a RETURN block