Try these - Convert replaces admin/GForum/Convert.pm, and setup_markup.html replaces admin/templates/admin/setup_markup.html. Then just go to Setup -> Markup, and you'll have the two new options. I made it only add the prefix/suffix only if there actually is a signature that contains something other than spaces.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com