If true, panning will always be animated if possible. If false, it will not
animate panning, either resetting the map view if panning more than a screen
away, or just setting a new offset for the map pane (except for panBy
which always does the latter).
Duration of animated panning.
Default value: 0.25.
The curvature factor of panning animation easing (third parameter of the Cubic Bezier curve). 1.0 means linear animation, the less the more bowed the curve.
Default value: 0.25.
If true, panning won't fire movestart event on start (used internally for panning inertia).
Default value: false.