return all matching rattrs if specified.  for example, 
	minooka; ndb/query sys kibbiee
	ip=205.185.197.14 ip=205.185.197.15 ip=205.185.197.16 sys=kibbiee ether=0030488b57c2 dom=kibbiee.coraid.com bootf=/386/9pxeload4 console=sukhoi 
	minooka; ndb/query sys kibbiee ip
	205.185.197.14
	205.185.197.15
	205.185.197.16
	minooka; /n/dump/2007/0718/386/bin/ndb/query sys kibbiee ip
	205.185.197.14

Notes:
Sun Aug 5 21:53:37 EDT 2007 geoff
    this might be the right thing to do,
    but it is a change of semantics and
    may break or at least disturb existing
    shell scripts.

Wed Aug 29 17:32:53 EDT 2007 geoff
    implemented as options and made a little more general.


Reference: /n/sources/patch/applied/query-allrattr
Date: Fri Jul 20 00:45:05 CES 2007
Signed-off-by: quanstro@speakeasy.net
Reviewed-by: geoff

--- /sys/src/cmd/ndb/query.c	Fri Jul 20 00:36:54 2007
+++ /sys/src/cmd/ndb/query.c	Fri Jul 20 00:36:53 2007
@@ -21,9 +21,13 @@
 	Ndbtuple *t, *nt;
 
 	if(rattr){
-		p = ndbgetvalue(db, &s, attr, val, rattr, nil);
+		p = ndbgetvalue(db, &s, attr, val, rattr, &nt);
+		for(t = nt; t; t = t->entry){
+			if(strcmp(t->attr, rattr) == 0)
+				print("%s\n", t->val);
+		}
 		if(p){
-			print("%s\n", p);
+			ndbfree(nt);
 			free(p);
 		}
 		return;