Revert "Merge external indexes into master"

This reverts commit 1a0d2b4b80677ddadb524503ad9c84e2f03aade7, reversing
changes made to 5eba6a0795f2278f4ea7747f8b54c858529b5502.
diff --git a/asterix-aql/src/main/javacc/AQL.jj b/asterix-aql/src/main/javacc/AQL.jj
index 8dd7bfb..cb6336b 100644
--- a/asterix-aql/src/main/javacc/AQL.jj
+++ b/asterix-aql/src/main/javacc/AQL.jj
@@ -308,11 +308,11 @@
     <LEFTPAREN> typeName = Identifier() <RIGHTPAREN>
     ifNotExists = IfNotExists()
     "using" adapterName = AdapterName() properties = Configuration()
-    ("on" nodeGroupName = Identifier() )?
     ( "hints" hints = Properties() )?
       {
-        ExternalDetailsDecl edd = new ExternalDetailsDecl(properties,
-        adapterName,nodeGroupName != null? new Identifier(nodeGroupName): null);
+        ExternalDetailsDecl edd = new ExternalDetailsDecl();
+        edd.setAdapter(adapterName);
+        edd.setProperties(properties);
         dsetDecl = new DatasetDecl(nameComponents.first,
                                    nameComponents.second,
                                    new Identifier(typeName),