Add high-level documentation to XSFBS shell library, intended to reduce user confusion when reading X package maintainer scripts outside the source tree.
Add high-level documentation to XSFBS shell library, intended to reduce
user confusion when reading X package maintainer scripts outside the source
tree.

Update Vim modeline.

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