Add copyright

Add copyright

SCCS-vsn: usr.bin/expand/expand.c 5.1
SCCS-vsn: usr.bin/finger/finger.c 5.1
SCCS-vsn: usr.bin/fold/fold.c 5.1
SCCS-vsn: usr.bin/from/from.c 5.1
SCCS-vsn: usr.bin/gcore/gcore.c 5.1
SCCS-vsn: usr.bin/gcore/gcore.c 5.2
SCCS-vsn: usr.bin/grep/old.ucb.grep/old.ucb.grep.c 5.1
SCCS-vsn: old/groups/groups.c 5.1
SCCS-vsn: usr.bin/head/head.c 5.1
SCCS-vsn: usr.bin/last/last.c 5.1
SCCS-vsn: usr.bin/lastcomm/lastcomm.c 5.1
SCCS-vsn: usr.bin/leave/leave.c 5.1
SCCS-vsn: usr.bin/lock/lock.c 5.1
SCCS-vsn: usr.bin/mkstr/mkstr.c 5.1
SCCS-vsn: usr.bin/printenv/printenv.c 5.1
SCCS-vsn: old/prmail/prmail.c 5.1
SCCS-vsn: bin/rcp/rcp.c 5.1
SCCS-vsn: usr.bin/tset/reset.c 5.1
SCCS-vsn: usr.bin/rsh/rsh.c 5.1
SCCS-vsn: usr.bin/ruptime/ruptime.c 5.1
SCCS-vsn: usr.bin/rwho/rwho.c 5.1
SCCS-vsn: usr.bin/sccs/sccs.c 5.1
SCCS-vsn: usr.bin/script/script.c 5.1
SCCS-vsn: usr.bin/soelim/soelim.c 5.1
SCCS-vsn: usr.bin/strings/strings.c 5.1
SCCS-vsn: old/symorder/symorder.c 5.1
SCCS-vsn: usr.bin/tail/tail.c 5.1
SCCS-vsn: usr.bin/telnet/telnet.c 5.1
SCCS-vsn: usr.bin/ul/ul.c 5.1
SCCS-vsn: usr.bin/unexpand/unexpand.c 5.1