Log message:
Import ruby200-ronn-0.7.3 as wip/ruby-ronn.

Ronn builds manuals. It converts simple, human readable textfiles
to roff for terminal display, and also to HTML for the web.
The source format includes all of Markdown but has a more rigid
structure and syntax extensions for features commonly found in
manpages (definition lists, link notation, etc.).
The ronn-format(7) manual page defines the format in detail.