Depend on the latest version of xfconf as it includes some bug fixes we
need for this to work.

Add FrapShortcutsProvider which acts as an abstraction layer over the
/default and /custom storage details. A FrapShortCutsProvider
represents a set of shortcuts, /commands or /xfwm4 for instance. It
automatically clones the default settings when created (if necessary)
and provides two signals: 'shortcut-removed' and 'shortcut-added'.

Rework the conflicts dialog, add a reset button the the keyboard
settings dialog and make the whole settings dialog code a GObject
(XfceKeyboardSettings).

(Old svn revision: 28074)