Merge branch 'merge-pull-87' into lammps-icms
From Tim Mattox:
Performance enhancements for USER-DPD, mostly in SSA communication:
- For an ideal fluid benchmark: ~15% speedup and ~5% memory savings
- Removes duCond and duMech, and replaces dvSSA with v_t0 (ghosts only)
- Eliminates the need to transmit deltas and uCond/uMech in
forward_comm
- Reduces "adds and loads" for computing updated velocities from v +
dvSSA