Chase Douglas authored Feb 09, 2012 and Peter Hutterer committed Mar 14, 2012

These values will be used for clickpad press and drag with two fingers.

While the clickpad button is not pressed, cumulative_d{x,y} will match x
and y values. Once the clickpad button is pressed, cumulative_d{x,y}
will be updated with the relative motion of each active touch on the
touchpad. This allows for dragging with one finger while another finger
stays stationary holding the clickpad button down.

This is an easier and less latent approach than trying to guess which
touch was the "dragging" touch.

[fixed build error for mt off]

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>