- tree hierarchy: when rendering non-"/" tree, it should start at that
  point, not from "/". eg. `pdescribe config.ini -T /path/to/foo` should
  result in:

    /path/to/foo/
    |-- sub-controller/
    |-- ...
    `-- ...

  instead of:

    /
    `-- path/
        `-- to/
            `-- foo/
                |-- sub-controller/
                |-- ...
                `-- ...

- force 'format' to lower case?... prolly - but where?

- make `DescriberController.formattext_html` try to load docutils, and
  if successful, do rST formatting with that. otherwise fallback to the
  pseudo-stuff...

- update DescribeController to inspect decorator `method` parameters

- add PDF support
