Adding eventListeners property to layer, control, and map. Setting this property at construction registers the given listeners based on event type key. r=elemoine (closes #1404)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@6435 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer.js

@@ -138,6 +138,15 @@ OpenLayers.Layer = OpenLayers.Class({
      */
     options: null,
 
+    /**
+     * APIProperty: eventListeners
+     * {Object} If set as an option at construction, the eventListeners
+     *     object will be registered with <OpenLayers.Events.on>.  Object
+     *     structure must be a listeners object as shown in the example for
+     *     the events.on method.
+     */
+    eventListeners: null,
+
     /**
      * APIProperty: gutter
      * {Integer} Determines the width (in pixels) of the gutter around image
@@ -272,6 +281,10 @@ OpenLayers.Layer = OpenLayers.Class({
 
             this.events = new OpenLayers.Events(this, this.div, 
                                                 this.EVENT_TYPES);
+            if(this.eventListeners instanceof Object) {
+                this.events.on(this.eventListeners);
+            }
+
         }
 
         if (this.wrapDateLine) {