Revision 210372

Add support for creating the archived log filenames using a time-stamp
instead of the traditional simple counter.

Using the time-stamp based file-names, once a log file is archived, it
will not change name until it is deleted.  This means that many backup
systems will only perform one backup of the archived log file, instead
for performing a new backup of the logfile upon each logfile rotation.

This implementation is separate from the patches in the mentioned PR,
as I wasn't aware of the existence of the PR until after I had
implemented the same functionality as the patches in the PR provide.
Unlike the PR, this new code does honor the 'log count' in
newsyslog.conf so old logfiles are deleted.  This new code does not
currently support never deleting the archived logfiles.

PR:		bin/29363
MFC after:	3 weeks