Now having a response handler, can reuse the open dialog several times in a row (and removed the save dialog bc/ not used yet)
Extra GLib marshallers
Added ConfirmOverwrite and a callback response method to the XML interface
TODO: must use enums in marshallers and on dbus signal definitions, if possible
Library: RFCD now receives Response signals and handles them, receives Destroy signals but does not handle them. LFCD now exports ConfirmOverwrite as well, but does not handle waiting
properly. Should build but is a WIP.