4.4BSD snapshot (revision 8.1); add 1993 to copyright

4.4BSD snapshot (revision 8.1); add 1993 to copyright

SCCS-vsn: usr.bin/mail/aux.c 8.1
SCCS-vsn: usr.bin/mail/cmd1.c 8.1
SCCS-vsn: usr.bin/mail/cmd2.c 8.1
SCCS-vsn: usr.bin/mail/cmd3.c 8.1
SCCS-vsn: usr.bin/mail/cmdtab.c 8.1
SCCS-vsn: usr.bin/mail/collect.c 8.1
SCCS-vsn: usr.bin/mail/def.h 8.1
SCCS-vsn: usr.bin/mail/edit.c 8.1
SCCS-vsn: usr.bin/mail/extern.h 8.1
SCCS-vsn: usr.bin/mail/fio.c 8.1
SCCS-vsn: usr.bin/mail/getname.c 8.1
SCCS-vsn: usr.bin/mail/glob.h 8.1
SCCS-vsn: usr.bin/mail/head.c 8.1
SCCS-vsn: usr.bin/mail/lex.c 8.1
SCCS-vsn: usr.bin/mail/list.c 8.1
SCCS-vsn: usr.bin/mail/mail.1 8.1
SCCS-vsn: usr.bin/mail/main.c 8.1
SCCS-vsn: usr.bin/mail/names.c 8.1
SCCS-vsn: usr.bin/mail/pathnames.h 8.1
SCCS-vsn: usr.bin/mail/popen.c 8.1
SCCS-vsn: usr.bin/mail/quit.c 8.1
SCCS-vsn: usr.bin/mail/rcv.h 8.1
SCCS-vsn: usr.bin/mail/send.c 8.1
SCCS-vsn: usr.bin/mail/strings.c 8.1
SCCS-vsn: usr.bin/mail/temp.c 8.1
SCCS-vsn: usr.bin/mail/tty.c 8.1
SCCS-vsn: usr.bin/mail/v7.local.c 8.1
SCCS-vsn: usr.bin/mail/vars.c 8.1
SCCS-vsn: usr.bin/mail/version.c 8.1