rewriten API for special events

I have some difficulties to see how it can works because nothing special is implemented in DefaultSpecialEvent

focusin and focusout is not simply aliases to focus and blur avent. The big difference is that focusin and focusout are bubbling events and focus and blur are not.

Take this exemple  (you should consider this example as test):

```html
<form id="myform">
  <input type="text" id="textInput1">
  <input type="text" id="textInput2">
</form>
```

``` java
$("#myform").on("focusin", new Function() {
   public void f(Element e) {
      console.log("One element of the form get the focus");
   }
});

// both calls should fire the focusin event handler above (won't work if we use focus instead of focusin)
$("#textInput1").focus();
$("#textInput2").focus();
```