Image commands
--------------

The image commands plugin allows you to run arbitrary commands during
the bootstrap process. The commands are run at an indeterminate point
*after* packages have been installed, but *before* the volume has been
unmounted.

Settings
~~~~~~~~

-  ``commands``: A list of lists containing strings. Each top-level item
   is a single command, while the strings inside each list comprise
   parts of a command. This allows for proper shell argument escaping
   (to circumvent this, simply put the entire command in a single
   string). In addition to the manifest variables ``{root}`` is also
   available. It points at the root of the image volume.
   *``required``*
   *``manifest vars``*