[#29] Re-added interface name to interface errors since abstract requirement change

lib/interface.js

@@ -209,6 +209,8 @@ var extend = ( function( extending )
 
         var new_interface = createInterface( iname );
 
+        try
+        {
             util.propParse( props, {
                 assumeAbstract: true,
 
@@ -239,6 +241,17 @@ var extend = ( function( extending )
                     );
                 },
             } );
+        }
+        catch ( e )
+        {
+            // alter the message to include our name
+            e.message = "Failed to define interface " +
+                ( ( iname ) ? iname : '(anonymous)' ) + ": " + e.message
+            ;
+
+            // re-throw
+            throw e;
+        }
 
         attachExtend( new_interface );
         attachStringMethod( new_interface, iname );