xdmenug.py access freedesktop menu entries via dmenu

Seems like an odd choice.  I'm already using dmenu several times a minute, why pollute it with freedesktop menus?  Because some distros hide and move things.  I can never remember what my cups config wizard is called, but configuring a printer can be really important.

Since M-x is $PATH dmenu, M-S-x made sense for this alternative dmenu.  This pushed my bookmarks script to M-g (since I use pentadactyl's gh for home, which is where my bookmarks are) and that freed up M-S-g for all history if I ever get around to it.
Cleared up tmux error