Improve support for barrel rotation in brush tools
@prokoudine
Submitted by Alexandre Prokoudine Link to original bug (#791455)
Description
Wacom's Art Pen supports a dynamic called barrel rotation which is covered by linuxwacom (xinput reportedly sees those events), but isn't handled by GIMP at all.
Rotation events should trigger changes in Brush Angle.
Demo of barrel rotation and, regrettably :), Photoshop CC: https://www.youtube.com/watch?v=1dtbEsQvohU.
Version: git master