Allow moused to accept userland mouse events
Allow moused to work with sysmouse when the port is a pipe,
not a real mouse device with working ioctls. Allows simple userland injection
of mouse events.
Attached is an example that works with the Griffin PowerMate
Just run `./scrollwheel.py scroller.fifo` as a user account, and then run `moused -p scroller.fifo -t sysmouse` as root.
If you press down the wheel, it will multiply scrolls by 32, so you can fly through code like in the movies.