Added support for mouse wheel events.
Added support for mouse wheel events.

libavg/libavg,libavg/libavg,libavg/libavg,libavg/libavg,hoodie/libavg,th3infinity/libavg,hoodie/libavg,th3infinity/libavg,th3infinity/libavg,hoodie/libavg,th3infinity/libavg,hoodie/libavg