port hid-multitouch to dde-linux

This is a port of the Linux hid-multitouch driver to dde-linux. It is tested with the Panasonic Toughpad FZ-M1. This patch also fixes #1207.

Limitations: 
- No support for finger tracking. Every contact triggers motion events.
- No generic mapping between the drivers absolute coordinates and mouse position in pixels. I did not find a nice way to do this. Let me know if you have any ideas.