Remove problematic (and unused) clone methods, move contains out of ol.Rectangle

src/ol/tilecoord.js

@@ -76,14 +76,6 @@ ol.TileCoord.createFromString = function(str) {
 };
 
 
-/**
- * @return {ol.TileCoord} Clone.
- */
-ol.TileCoord.prototype.clone = function() {
-  return new ol.TileCoord(this.z, this.x, this.y);
-};
-
-
 /**
  * @return {number} Hash.
  */