xsfbs: add a repack script for uscan
xsfbs: add a repack script for uscan

This will automatically prune upstream tarballs

facboy/xserver-xorg-video-qxl,philipn/xserver-xorg-input-synaptics,RsrchBoy/xserver-xorg-input-synaptics,facboy/xserver-xorg-video-qxl,philipn/xserver-xorg-input-synaptics,RsrchBoy/xserver-xorg-input-synaptics,facboy/xserver-xorg-video-qxl,philipn/xserver-xorg-input-synaptics,facboy/xserver-xorg-video-qxl