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
