Updated and improved manpage

The current manpage has not been updated for 9 years (!!!). It also does not follow many of the conventions laid out for manpages. 

I have submitted a revised and improved version. Please feel free to edit it, especially to rearrange the various options.

I have left it in an un-gzipped format for easier editing.

This is being incorporated as a patch in the Debian package (pending approval).

Caitlin