radio and checkbox buttons no longer work (2.0.1)

Created by: rvagg

Since 139a0775, also picked up by @deytao

I guess either go back to event.target or switch the delegate selector to something like '[data-toggle^=button] .btn' causecurrentSelector` is set to the element matched by the delegate selector (even Bean does this now btw!) and at the moment it's the parent of the buttons. See docs/javascript.html, they don't work.