menu settings, backdrop list selection

[Brian J. Tarricone]

hi all-

i finally added the options to the desktop settings panel to control the 
menu.  you can enable/disable the window list or the desktop menu, and 
for each you can choose whether or not to display icons.  the panel 
plugin also now has an option to show icons in the menu.

i also added the feature requested on the xfce ML.  the edit backdrop 
list dialog will now preselect the backdrop that's currently set, and it 
puts an asterisk before and after the filename.  i tried to make it bold 
or italicise the name, but from what i could find on the topic, doing 
pango-ish stuff to the GtkCellRenderer is a pain, and i don't think it's 
worth the effort.

moritz: i haven't tested the new stuff with --disable-desktop-menu.  let 
me know if there are any problems.  the settings panel should get 
compiled without desktop menu settings as well.  i'm thinking of 
removing --disable-desktop-menu at some point, because disabling it from 
the settings panel has the same effect - the module gets unloaded, and 
xfdesktop checks the setting at startup to see if it should even bother 
loading the module.  the only difference is in code size for the 
xfdesktop binary (minor, i'd think), and the fact that you have an 
unused shared lib bumming around in /usr/lib/xfce4/modules/.  what do 
you think?  ditch the configure option?

yay, my todo list is getting shorter:
- fix app-crashing problem
- usability tweaks for the backdrop settings
- xinerama
- desktop menu cleanups

and now i shall take a 3 hour nap before i go to work =p.

    -brian