Removes a problem where any body with a mass matrix with unequal principal axes gains energy when rotating with gyroscopicMode set to true (the default).
Changes the computation of gyroscopic torques in step.cpp and quickstep.cpp to use an implicit computation. This is more computational expensive, but usable. The other method is not usable for freely rotating bodies. When the inertia matrix has equal principal axes, the gyroscopic computation does nothing; so it might as well be disabled to save cycles.
See video: www.youtube.com/watch?v=RHqyKfxWNpY