(1) PairlistDistance is properly passed on to ComputeForce objects;
  (2) Power of 2 threads are now used in particle-grid force reduction;
  (3) Fixed accidental transpose of threads and blocks in grids' particleList kernel call

Implemented "particleLists" for rigid body--particle interactions; made RigidBodyType class manage its own device data for particle interactions

removed volatile tricks that reduced registers since overall performance was degraded (154 regs; ~3 ms/step with tRNA)

Attempt to parallelize kernel; Added names to multiple instances of an RB; rotation integration still appears flawed

searching for bugs, found some; appears that in integration, torque rotates the object the wrong way!