Pass the correct event.currentTarget on delegation

[giuseppeg]

Removes data.el from the event data payload
Fixes #290

[tgvashworth]

Thanks for this @giuseppeg.

For backward compatibility I'd like to keep data.el, otherwise this needs to go out with a major version bump (well, for this semver-ish project it's minor), not to mention a load of refactoring in TweetDeck. Can we just add currentTarget and the test?

[giuseppeg]

@PhUU I guess we can. Let's see what the other people think about it.

[tgvashworth]

Gonna close this cos I've put up another with some fixes (#329) — not sure of a better way to contribute to your pull!

[giuseppeg]

sure np