Fix issue with DOM layers in wrong order

When removing/inserting layers back-to-back, the layer elements can
get out of order because createLayerRenderer always appends to the
layer pane. This makes it always reattach the layer node at the
correct index, ensuring correct layer ordering.

src/ol/renderer/dom/dommaprenderer.js

@@ -71,7 +71,6 @@ ol.renderer.dom.Map.prototype.createLayerRenderer = function(layer) {
     goog.asserts.fail();
     return null;
   }
-  goog.dom.appendChild(this.layersPane_, layerRenderer.getTarget());
   return layerRenderer;
 };
 
@@ -94,7 +93,9 @@ ol.renderer.dom.Map.prototype.renderFrame = function(frameState) {
   var i, ii, layer, layerRenderer, layerState;
   for (i = 0, ii = layersArray.length; i < ii; ++i) {
     layer = layersArray[i];
-    layerRenderer = this.getLayerRenderer(layer);
+    layerRenderer = /** @type {ol.renderer.dom.Layer} */ (
+        this.getLayerRenderer(layer));
+    goog.dom.insertChildAt(this.layersPane_, layerRenderer.getTarget(), i);
     layerState = frameState.layerStates[goog.getUid(layer)];
     if (layerState.sourceState == ol.source.State.READY) {
       layerRenderer.prepareFrame(frameState, layerState);