Merge pull request #410 from probins/fixzoom

Fix Map so zoomChanged when zoom is constructor option

lib/OpenLayers/Map.js

@@ -662,6 +662,7 @@ OpenLayers.Map = OpenLayers.Class({
              * be properly set below.
              */
             delete this.center;
+            delete this.zoom;
             this.addLayers(options.layers);
             // set center (and optionally zoom)
             if (options.center && !this.getCenter()) {