Commit JT 051118 before CEA

examples/SPIN/read_restart/in.spin.read_data

examples/SPIN/read_restart/in.spin.restart

examples/SPIN/read_restart/in.spin.write_restart

src/SPIN/compute_spin.cpp

src/SPIN/fix_langevin_spin.cpp

src/SPIN/fix_nve_spin.cpp

src/SPIN/fix_nve_spin.h

src/SPIN/fix_precession_spin.cpp

src/SPIN/pair_spin_dmi.cpp

src/SPIN/pair_spin_dmi.h

src/SPIN/pair_spin_exchange.cpp

src/SPIN/pair_spin_exchange.h

src/SPIN/pair_spin_me.cpp

src/SPIN/pair_spin_me.h

src/SPIN/pair_spin_neel.cpp