extendable custom events for bean

[eleith]

how it works:

1. expose bean.customEvents out in the open
2. allow for customEvents to have base, handler and condition fields
3. on add/bind (on a custom event with both a base and a handler), register a listener for the base type using the custom handler and normally register a listener for the custom event
4. custom handler should eventually lead to a fire/trigger on the custom event type

here is an example of how to extend the custom events with a basic tripleclick event

bean.customEvents.threeclicks = {
      base: 'click',
      handler: function(event)
      {
        var elem = this, clicks = this.__threeclicks__ || 0;
        clicks += 1;
        if ( clicks === 3) {
            clicks = 0;

            // set event type to "tripleclick"
            event.type = "threeclicks";

            //FIRE AWAY
            bean.fire(this, "threeclicks", event);
        }
        this.__threeclicks__ = clicks;
      }
    }

to register the event:

bean.add(element, "tripleclick", function() { alert('triple clicked!'); });

to remove the event:

bean.remove(element, "tripleclick")

it should still support namespacing, using the element/ender object as context in the handlers, and all the different ways add/remove can be called.

i've also added these examples in the tests.js framework to show (and prove) how add/remove works on these extended custom events.

[eleith]

some of the previous commits on bean for adding the one method are showing up as additions in my diffs. not sure why, but those are in the current master branch, so they shouldn't be there.

[rvagg]

FWIW, I'm still mindful of this PR and I think that customEvents should be made public in some way but I don't think it' flexible enough as it is, I wouldn't mind seeing it able to better handle extensions such as #50 and perhaps other crazy additions. At the moment, the uses of customEvents is just to limited.