Change ol.BrowserFeature.HAS_POINTER feature detection

Because navigator.pointerEnabled will not be part of the final spec.
See https://www.w3.org/Bugs/Public/show_bug.cgi?id=22890

externs/closure-compiler.js

@@ -52,12 +52,3 @@ Document.prototype.msFullscreenEnabled;
 
 /** @type {Element} */
 Document.prototype.msFullscreenElement;
-
-
-// @see https://code.google.com/p/closure-compiler/issues/detail?id=1276
-
-/**
- * @type {boolean}
- * @see http://www.w3.org/TR/pointerevents/#widl-Navigator-pointerEnabled
- */
-Navigator.prototype.pointerEnabled;