Updated mod_opal to latest stable OPAL version.

Enhancements to trace logging, include threads and context ID.

Changed default opal_conf.xml to allow more than just G.711 uLaw and not to clutter log file with debug logs.

Added to opal_conf.xml item for "disable-transcoding".

Updated build/buildopal.sh to use correct ./configure items for PTLib, allow for something other than standard install directory for PTLib/OPAL and be able to easily bind to a specific release of PTLib/OPAL.

conf/vanilla/autoload_configs/opal.conf.xml

@@ -1,12 +1,14 @@
 <configuration name="opal.conf" description="Opal Endpoints">
   <settings>
-    <param name="trace-level" value="4"/>
+    <param name="trace-level" value="3"/>
     <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 -->
+    <param name="jitter-size" value="40,100"/>                <!-- Jitter buffer min/max size, milliseconds -->
+    <!-- <param name="codec-prefs" value="PCMU,PCMA"/> -->    <!-- list, and preferecnce order, of codecs -->
+    <!-- <param name="disable-transcoding" value="true"/> --> <!-- do not transcode, use source channel codec only -->
+    <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="$${local_ip_v4}"/>      <!-- optional listener interface name -->
   </settings>
   <listeners>
     <listener name="default">