Ticket 3939 - Option to animate children elements in animateClass

[gnarf]

http://bugs.jqueryui.com/ticket/3939

Usage:

$("#element").toggleClass( "className", {
  duration: 200,
  children: true,
  easing: "swing",
  complete: fn
});

Note that all of the base jQuery functions that take speed, easing, callback can also take { duration: speed, easing: easing, complete: callback } as the speed option for equivalency. I updated the animateClass function to use jQuery.speed() to take extra arguments using the same form and added a o.children option that when truthty causes animateClass to look at the children elements as well.