Print help for humans, fixes #124

[techtonik]

>py "gl.py"
Gitless: a version control system built on top of Git.
More info, downloads and documentation at http://gitless.com

commands:

    track               start tracking changes to files
    untrack             stop tracking changes to files
    status              show status of the repo
    diff                show changes to files
    commit              save changes to the local repository
    branch              list, create, delete, or edit branches
    tag                 list, create, or delete tags
    checkout            checkout committed versions of files
    merge               merge the divergent changes of one branch onto another
    resolve             mark files with conflicts as resolved
    fuse                fuse the divergent changes of a branch onto the current branch
    remote              list, create, edit or delete remotes
    publish             publish commits upstream
    switch              switch branches
    init                create an empty Gitless's repository or create one from an existing remote repository
    history             show commit history

[spderosso]

thanks!