Add a new `drupal-permissions` Ansible role that resets the file and
directory permissions to match the ones described in
https://www.drupal.org/node/244924.
This will later be released to Ansible Galaxy, but for now it will
remain in this repository until the required changes are made and the
appropriate documentation is added.
Fixes#191
Now that the Drupal settings role is on Ansible Galaxy, it can be added as a requirement and installed from there rather than having a local copy in the codebase.
Fixes#15