blackberry/Ripple-UI — pull request #644 by brentlintner (2012-12-06 21:59:36+00:00)
Title: Throw a helpful error when registering for an unsupported (BB10) event.

Take this example:

blackberry.event.addEventListener("onaccesschanged", function () {})

If an unsupported event name is registered for, it would throw an error
like this:

Uncaught TypeError: Cannot read property 'callbacks' of undefined.

Now, it will throw a `new Error(..)` with a message like this:

Uncaught Error: Cannot register a handler for the onaccesschanged
event, because it does not seem to be supported.

This commit is related (but does not fix) to this GitHub issue:

https://github.com/blackberry/Ripple-UI/issues/629