Handle mouse wheel
Handle mouse wheel

The RDP compositor was ignoring mouse wheel events, this patch adds
support for it.

udoprog/weston,Fantu/compositor-spice,kwm81/weston,giucam/weston,krezovic/weston,sir-murray/weston,Gnurou/weston,mchalupa/weston,jonnylamb/weston,sir-murray/weston,Fantu/compositor-spice,Fantu/compositor-spice,jonnylamb/weston,xorgy/weston,xorgy/weston,eyolfson/weston,eyolfson/weston,Tarnyko/weston-xdg_surface_present,Gnurou/weston,udoprog/weston,giucam/weston,Tarnyko/weston-xdg_surface_present,kwm81/weston,krezovic/weston,mchalupa/weston