Do not allow RemoteUserCpu to go backwards.  HTCONDOR-1162
Do not allow RemoteUserCpu to go backwards.  HTCONDOR-1162

Hopefully this patch will fix observed behavior where
RemoteUserCpu and RemoteSysCpu will sometimes end up with zero
values in the history file, while CumulativeRemoteUserCpu is > 0.

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor