Add `--version` option to all commands.
Add `--version` option to all commands.

Reviewers: danf, tail

Reviewed By: tail

Differential Revision: http://phabricator.local.disqus.net/D16996

fuziontech/pgshovel,disqus/pgshovel,disqus/pgshovel,fuziontech/pgshovel,fuziontech/pgshovel