Domain decomposition now checks the rlist buffer

When a large pair-list buffer, which will appear with large nstlist,
atoms are allowed to displace the buffer size, i.e. a lot, in nstlist
steps. The limit this puts on the DD cell size is now checked.
Also updated cg_move_error, which now no longer prints the old atom
coordinates with the Verlet scheme, where the "old" coordinates are
actually the new ones.
Fixes #1607.

Change-Id: I784afa5ee620b51f555f4d1107f38cbbae2c55d1