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
* Add modules for gathering facts about ZFS datasets and pools
* Move zfs module to storage/zfs subcategory
* Replace dict.iteritems() with iteritems(dict)
* Add ANSIBLE_METADATA
Document return values
Make imports explicit
Use native YAML syntax in EXAMPLES
* Add zfs_facts and zpool_facts modules to CHANGELOG.md
* Add facts to return values
Toshio Kuratomi
Adam Števko