JRuby port

[Anthony Elizondo]

JRuby is a Ruby interpreter written in Java. It allows to access Java
classes from within Ruby and in Ruby's syntax. A new version 0.8.3,
was released on 2006.03.27. Read more at http://jruby.sf.net/

The version currently in ports is quite outdated and I would like to
try to tackle trying to update it, if nobody else is working on it. I
see no PRs open on it.

Anthony