Adding a bit of flexibility to extend and applyDefaults. First argument can now be undefined. r=pspencer,elemoine (closes #1564)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@7311 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/MapServer.js

@@ -42,12 +42,9 @@ OpenLayers.Layer.MapServer = OpenLayers.Class(OpenLayers.Layer.Grid, {
         newArguments.push(name, url, params, options);
         OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
 
-        if (arguments.length > 0) {
-            OpenLayers.Util.applyDefaults(
-                           this.params,
-                           this.DEFAULT_PARAMS
-                           );
-        }
+        this.params = OpenLayers.Util.applyDefaults(
+            this.params, this.DEFAULT_PARAMS
+        );
 
         // unless explicitly set in options, if the layer is transparent, 
         // it will be an overlay