Force field updates.

New order for SWM4-NDP and SWM6 topologies, with SETTLE
instead of 3 constraints.  Performance is slightly better
in this case.  Uploading a SWM4-NDP water box that has
been equilibrated for 100 ps to serve as input for gmx
solvate.

Change-Id: I67e10693ca76e77b99b371ea9887402e7ac0acc1