Relative motion support

[AutoImport-neilisaac]

I forked this (and the driver) and added an option to support relative input for touch input. This will open up a lot of options for gesture-based input such as two-finger scrolling or two/three fingers for right/middle click which I plan to implement soon. Feel free to give it a try and let me know if you’re interested in merging it at some point.

[rfc2822]

Thanks! I’m very happy that the project is used by other people and at some time, when the code base has proven stability, I will be happy to merge other people’s additions.