Added gatekeeper support.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@12878 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/autoload_configs/opal.conf.xml

@@ -4,6 +4,9 @@
     <param name="context" value="default"/>
     <param name="dialplan" value="XML"/>
     <param name="codec-prefs" value="PCMU"/>
+    <param name="gk-address" value=""/>    <!-- empty to disable, "*" to search LAN -->
+    <param name="gk-identifer" value=""/>  <!-- optional name of gk -->
+    <param name="gk-interface" value=""/>  <!-- optional listener interface name -->
   </settings>
   <listeners>
     <listener name="default">