Short-term
 * Accept command line argument to allow rollback of a specific backend
 * Remove backends list and rely on the above command line argument
 * Add logic in the control center to activate this capplet with the
   appropriate command line argument from menu items or a control
   connected with each capplet
 * Something that tells the user when he tries to go back so far in
   time that there is no configuration available from that date
 * Have config manager dialog set flag when rolling back and, upon
   cancel, only roll forward if that flag is set

Long(er)-term
 * Somehow fix this so that the user sees the old configurations as he
   selects a time. The selection should be a slider that the user slides
   back and forth to roll forwards and backwards, and the user should see
   the configuration settings as reflected in the position of the slider.
	- This could just be put into libcapplet, so that the user
	  sees this slider at all times. That could be a bit much for a lot of
	  users, though.
	- This could be a bonobo component, acting as a container for
	  capplets (which are then bonobo controls).
	- This could be a feature of libcapplet enabled by a command
	  line switch

Done
 * Get this thing to actually work
 * Accept command line argument to tell whether it's going to be user
   or global