[ODE] dParamVel Slider

[Marco Grubert]

Hello,

I was just playing around with the motor slider and for some reason it will
only move in one direction.
dJointSetSliderParam( myJoint, dParamVel, 1 ); and
dJointSetSliderParam( myJoint, dParamVel, -1 );
both make the attached object move in the same direction. Flipping the order
in which the objects are attached, e.g. dJointAttach( myJoint, body1, body2)
vs. dJointAttach( myJoint, body2, body1) did flip the direction.

Feature / bug / user error ?

- Marco Grubert