Resource debug / describe command.

[dantleech]

When #29 is merged, then I think it would make sense to add a command for debugging /describing resources, e.g.

$ ./bin/console debug:cmf-resource /path/to/resource --repository=default
name: Foobar
type: phpcr
payload_type: nt:foobar
description:
     link_edit_html: /edit/foobar/1234
     link_list_html: /foobars