put in beginnings of mod time checks on maps; generalize flags

put in beginnings of mod time checks on maps; generalize flags
parameter to parseaddr/allocaddr to use RF_ hooks; relax HELO rules
for Authentication-Warning:s

SCCS-vsn: usr.sbin/sendmail/src/recipient.c 8.15
SCCS-vsn: usr.sbin/sendmail/src/envelope.c 8.8
SCCS-vsn: usr.sbin/sendmail/src/parseaddr.c 8.7
SCCS-vsn: usr.sbin/sendmail/src/sendmail.h 8.13
SCCS-vsn: usr.sbin/sendmail/src/savemail.c 8.10
SCCS-vsn: usr.sbin/sendmail/src/srvrsmtp.c 8.12
SCCS-vsn: usr.sbin/sendmail/src/alias.c 8.8
SCCS-vsn: usr.sbin/sendmail/src/map.c 8.8