[ODE] possible bug regarding dJointAddHingeTorque and dJOINT_REVERSE

[jon klein]

In the code for dJointAddHingeTorque, it checks dJOINT_REVERSE to 
determine
the sign of the torque to be added.  Is this really correct?  This means
that depending on the argument order of dJointAttach (which determines 
the
state of dJOINT_REVERSE), that the same call to dJointAddHingeTorque can
cause joint motion in opposite directions.

- jon