Huion tilt support done
Added 2019-03-25 08:09:20 +0000 UTCI printed the protractor on the weekend, and compared the Huion tilt reports to Wacom tilt reports. The Wacom reports (from the kernel driver) turned out to be pretty close to degrees, but Huion reports not so much. Still, I couldn't see an easy and consistent way to get them closer in the driver, so I simply declared the resolution to be one degree. Although the reports go up to 60, the actual angles are closer to 56 degrees. This will have to be enough though. The amended code is pushed to the repository and is available in the latest development version.
