Restructure the time processing routines, mainly to fix up the

Restructure the time processing routines, mainly to fix up the
"will trim at" message printed when the user requests '-v'.  The
previous code would often print the wrong time, such as:
On Sept 22, run:   newsyslog -nv /var/log/wtmp
        And see:   will trim at Mon Sep  1 05:00:00 2003
    correct msg:   will trim at Wed Oct  1 05:00:00 2003

MFC after:	20 days