Revert "Merge pull request #116 from elemoine/redraw"

This reverts commit 7a5b469192, reversing
changes made to a719de7e93.

Conflicts:

	tests/Tile/Image.html

lib/OpenLayers/Layer/HTTPRequest.js

@@ -122,7 +122,6 @@ OpenLayers.Layer.HTTPRequest = OpenLayers.Class(OpenLayers.Layer, {
      */
     mergeNewParams:function(newParams) {
         this.params = OpenLayers.Util.extend(this.params, newParams);
-        this.resolution = null;
         var ret = this.redraw();
         if(this.map != null) {
             this.map.events.triggerEvent("changelayer", {
@@ -147,7 +146,7 @@ OpenLayers.Layer.HTTPRequest = OpenLayers.Class(OpenLayers.Layer, {
         if (force) {
             return this.mergeNewParams({"_olSalt": Math.random()});
         } else {
-            return OpenLayers.Layer.prototype.redraw.call(this);
+            return OpenLayers.Layer.prototype.redraw.apply(this, []);
         }
     },