docs(angular.element): note restrictions of addClass and removeClass

Closes angular#12851
Closes angular#12793

Author: Narretz

src/jqLite.js

@@ -51,7 +51,7 @@
  * ## Angular's jqLite
  * jqLite provides only the following jQuery methods:
  *
- * - [`addClass()`](http://api.jquery.com/addClass/)
+ * - [`addClass()`](http://api.jquery.com/addClass/) - Does not support a function as first argument
  * - [`after()`](http://api.jquery.com/after/)
  * - [`append()`](http://api.jquery.com/append/)
  * - [`attr()`](http://api.jquery.com/attr/) - Does not support functions as parameters
@@ -78,7 +78,7 @@
  * - [`ready()`](http://api.jquery.com/ready/)
  * - [`remove()`](http://api.jquery.com/remove/)
  * - [`removeAttr()`](http://api.jquery.com/removeAttr/)
- * - [`removeClass()`](http://api.jquery.com/removeClass/)
+ * - [`removeClass()`](http://api.jquery.com/removeClass/) - Does not support a function as first argument
  * - [`removeData()`](http://api.jquery.com/removeData/)
  * - [`replaceWith()`](http://api.jquery.com/replaceWith/)
  * - [`text()`](http://api.jquery.com/text/)