Loading over DBus is a tiny bit slower, but makes
it a lot easier to change values and also saves a
lot of hassle with modified properties.

Nearly all gtk 2.24 distros have 2.32 or newer, so
don't depend on 2.28 and use 2.30.

We already require GVFS for a trash implementation, so
why ot rely on the metadata storage too.

Manual has been moved to http://docs.xfce.org/xfce/thunar/start