[Seaside] JQDroppable convience method

[Lukas Renggli]

> That's right but $(this) is bound to the droppable, while it's often
> convenient to get the object that was dragged onto it (the draggable).
> Using the trigger:passengers: approach, it seems impossible to me to get to
> the draggable.
>
> Or am I missing something?

No, this is jQuery that is missing something ;-)

Currently there is almost no support to get the parameters from events
back into the image. I will add some helper methods to JQAjax to make
this simpler. I am not particularly fond of adding something like
#onDropCallback: because this hardcodes an AJAX request and does not
give the user the possibility to define additional AJAX actions,
render something, change something, etc.

Lukas

-- 
Lukas Renggli
http://www.lukas-renggli.ch