Fix lags in Move Tool when using tablet device
Now the Move Tool uses the same FSP-limiting compression as the freehand
tool does. The relevant code has been moved into a special class
KisAsyncronousStrokeUpdateHelper, which implements a logic of issuing
Bascially, all the sources of event (tablet move and async update from
KisAsyncronousStrokeUpdateHelper) now try to initiate a canvas update.
If enough time has passed and previous updates has finished, then a new
update is started.
One more important change: now actual layer offset change is executed in
the same exclusive job as the updates (with limited FPS), therefore, it
avoids garbage-looking leftovers of the intemediate move states.