This patch makes the main modifier configurable. We used to hardcode super
(windows key) for most bindings, but now that can be changed.
The change affects two key bindings: rotation moves to mod+right click
and backlight moves to from ctrl+f9/f10 to mod+f9/f10.
Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>