Patch to empty selectedFeatures when destroying all features from #665,

tschaub. This includes tests (hooray) and fixes issues with zooming a wfs
layer while you have a feature selected.


git-svn-id: http://svn.openlayers.org/trunk/openlayers@3067 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Vector.js

@@ -26,7 +26,7 @@ OpenLayers.Layer.Vector.prototype =
     features: null,
     
     /** @type Array(OpenLayers.Feature.Vector) */
-    selectedFeatures: [],
+    selectedFeatures: null,
 
     /** @type {Boolean} */
     reportError: true, 
@@ -252,8 +252,10 @@ OpenLayers.Layer.Vector.prototype =
     },
 
     /**
+     * Destroy all features on the layer and empty the selected features array.
      */
     destroyFeatures: function () {
+        this.selectedFeatures = new Array();
         for (var i = this.features.length - 1; i >= 0; i--) {
             this.features[i].destroy();
         }