Added logging for troubleshooting.
Rewrote the javascript component & added separate callbacks per Ken Vu's
ideas.

cref. https://github.com/kenvunz/cordova-ios-LocalNotification/commit/035baa0a82727f7750beb79d63bb00789459a2be
Since id is coming from JS, widen the scope of equality.
Tidying whitespace & readme.