#102 Provide nightly builds

[sky_HALud]

Nightly builds are a very useful way of keeping
interested users updated with the evolution of
JCommander. It is also very useful in regularly
checking that, once set up, the automated build is
working well.

JavaForge provides a mechanism to run scheduled builds.
Here it is detailed how to proceed:
http://www.javalobby.org/nl/archive/jlnews_20051011o.html