Support cloning gists

[michaelorr]

Gists are fully established repos and can be interacted with as such. There should be an action gists clone GIST_ID [path] which would clone the specified gist to either the current directory or the path specified. This would allow the user to interact with the gist as a repo, commit files to it and push it back up to the remote.

[khilnani]

Good suggestion, ill take a look