suzerain: #3116 combat periodic drift

Was observing drift between restart and statistics file times
stemming from statistics being every_dt/N for small N.  Over
time this caused drift between the two events when they were
intended to be synchronized.  This logic, I think, keeps them
merged preventing such inter-event drift (though intra-event
drift may now appear as a side-effect).

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45354 0bd85f0b-c151-43b9-a1e9-27231104551f