New example - opentrack head-tracking to mouse events #181

I just uploaded a opentrack-mouse gist. The gist reads the UPD-protocol output from opentrack (a head tracker), and uses evdev to inject the mouse move events. I thought it might be a useful example to mention here.

One thing to note. In the gist, the injection of mouse events silently failed until I included buttons in the capabilities passed to UInput. This may be a issue with the underlying library because a stackoverflow post reported a similar issue that was resolved in the same way (by adding buttons).