Merge pull request #27 from timattox/USER-DPD_kokkos_update

Merge changes thru July 27, 2017 from master 6d0a2286 into USER-DPD_kokkos

Includes 67a0183b which partially reverted 7f9a331c (from May 16, 2017) in USER-DPD,
since SSA neighbor lists use ghost info, so they can't currently be used as "occasional" lists.