Due to the lookahead, small changes in the direction of the toolhead
cause minor changes in toolhead velocity. These "cornering" velocity
changes cause the current extruder code to trigger pressure advance
and its associated pressure retract. This causes the extruder to
rapidly "jerk" the filament.
This code change updates the extruder to detect velocity changes due
solely to cornering and avoid pressure advance.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor