MR number two for the new gesture tracker and probably the most important (and also complicated) one, actually introducing the new tracker and implementing the coordination between gestures sharing points and gestures not sharing points/on different actors.
This also includes two commits making the traditional event delivery machinery behave nicely while gestures are active, not emitting mouse/touch events while a gesture is recognizing, and also inhibiting crossing events while gestures are active.
Depends on (and includes) !2342