Revert "Merge pull request openlayers#432 from ahocevar/iframe-opacity"

This reverts commit af046b9, reversing
changes made to f36fd5f. The reason for reverting this is that the change breaks the select-feature-multilayer.html example.

lib/OpenLayers/Layer.js

@@ -1286,12 +1286,7 @@ OpenLayers.Layer = OpenLayers.Class({
             this.opacity = opacity;
             var childNodes = this.div.childNodes;
             for(var i = 0, len = childNodes.length; i < len; ++i) {
-                var element = childNodes[i].lastChild || childNodes[i];
-                if (element.nodeName.toLowerCase() === "iframe") {
-                    // changing opacity on IFrame elements does not work, so
-                    // we set it on the parent
-                    element = element.parentNode;
-                }
+                var element = childNodes[i].firstChild || childNodes[i];
                 OpenLayers.Util.modifyDOMElement(element, null, null, null, 
                                                  null, null, null, opacity);
             }

lib/OpenLayers/Renderer/SVG.js

@@ -470,7 +470,7 @@ OpenLayers.Renderer.SVG = OpenLayers.Class(OpenLayers.Renderer.Elements, {
      */
     createDefs: function() {
         var defs = this.nodeFactory(this.container.id + "_defs", "defs");
-        this.rendererRoot.insertBefore(defs, this.root);
+        this.rendererRoot.appendChild(defs);
         return defs;
     },
 

lib/deprecated.js

@@ -5256,7 +5256,7 @@ OpenLayers.Renderer.SVG2 = OpenLayers.Class(OpenLayers.Renderer.NG, {
      */
     createDefs: function() {
         var defs = this.nodeFactory(this.container.id + "_defs", "defs");
-        this.rendererRoot.insertBefore(defs, this.root);
+        this.rendererRoot.appendChild(defs);
         return defs;
     },