Removing deprecated events syntax.

Removing deprecated events syntax.

BUG=

Committed: https://code.google.com/p/dart/source/detail?r=18459

[Emily Fortuna, 2013-02-12 01:40:17]

lgtm!

[blois, 2013-02-12 02:06:34]

I missed removing some of the EventTarget APIs, which exposed an issue in the JS
interop.

Ended up keeping the on['eventname'] syntax for ease of use, but having it
return a stream.

PTAL

[Emily Fortuna, 2013-02-12 17:49:40]

lgtm. Don't we need the on['foo'] syntax for referencing custom events, anyway?
Or is there a better way to do that?

[blois, 2013-02-12 18:02:04]

On 2013/02/12 17:49:40, Emily Fortuna wrote:
> lgtm. Don't we need the on['foo'] syntax for referencing custom events,
anyway?
> Or is there a better way to do that?

Recommended way is to declare an EventStreamProvider, to avoid the dependency on
strings and easily capture bubbling events.