xfce-utils: update to 4.8.3

* relative-symlinks-docs.patch was applied mainline [1]
* run tested on overo

[1] http://git.xfce.org/xfce/xfce-utils/commit/?id=6d76b3625dd5ad2206a9c17575e22d99d43c8ecc



Signed-off-by: Andreas Müller <schnitzeltony@gmx.de>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>