Turn on glue-cache by default

- We decided to do this on the weekly BIND dev meeting
- Mark reviewed patch on Jabber

bin/named/config.c

@@ -138,7 +138,7 @@ options {\n\
 #	sortlist <none>\n\
 #	topology <none>\n\
 	auth-nxdomain false;\n\
-	glue-cache no;\n\
+	glue-cache yes;\n\
 	minimal-any false;\n\
 	minimal-responses true;\n\
 	recursion true;\n\

doc/arm/Bv9ARM-book.xml

@@ -6406,11 +6406,12 @@ options {
 		  delegate to a child zone.
 		</para>
 		<para>
-		  The glue cache uses memory proportional to the
-		  number of delegations in the zone. The default
-		  setting is <userinput>no</userinput>. Setting it to
-		  <userinput>yes</userinput> will improve performance
-		  at the cost of increased memory usage for the zone.
+		  The glue cache uses memory proportional to the number
+		  of delegations in the zone. The default setting is
+		  <userinput>yes</userinput> which improves performance
+		  at the cost of increased memory usage for the zone. If
+		  you don't want this, please set it to
+		  <userinput>no</userinput>.
 		</para>
 		<para>
 		  The glue cache is only used when