Generalise locally-configured CNAME handling.

It's now possible for the target of a CNAME to be any locally
configured RR or even point to a non-existent RR.

src/rfc1035.c

@@ -788,7 +788,7 @@ int extract_addresses(struct dns_header *header, size_t qlen, char *name, time_t
 		      if (newc)
 			{
 			  newc->addr.cname.target.cache = NULL;
-			  /* anything other than zero, to avoid being mistaken for CNAME to interface-name */ 
+			  /* anything other than zero, to avoid being mistaken for a local CNAME */ 
 			  newc->addr.cname.uid = 1; 
 			  if (cpp)
 			    {