Refactoring to suit more needs

* Use proper indentation for Python (4 spaces and not tabs)
* If repo is not yet cloned, try to clone it instead of erroring
* Can also be used to deploy *any* repo:
    To enable this behaviour, just set `repositories` to `null` in the
    config. Also set `global_path` to the path where these repositories
    should be cloned. Then, any incoming hook will be processed, the
    repo cloned and the `global_deploy` commands run. Beware, this can
    be a real security risk if your listener is publicly accessible.