If this Body is using drag for deceleration this property controls how the drag is applied.
If set to true drag will use a damping effect rather than a linear approach. If you are
creating a game where the Body moves freely at any angle (i.e. like the way the ship moves in
the game Asteroids) then you will get a far smoother and more visually correct deceleration
by using damping, avoiding the axis-drift that is prone with linear deceleration.
If you enable this property then you should use far smaller drag values than with linear, as
they are used as a multiplier on the velocity. Values such as 0.05 will give a nice slow
deceleration.