selectize.addOption() only called once for entire options array

I moved everything from `objectWasAdded` into `contentArrayDidChange` because it makes the plugin work faster and because `selectize.addOption()` only needed to be called once. While this works for me, I'm not confident that I haven't missed anything. If you have time, throw your suggestions my way and I'll update. Cheers!
Are you sure you can do this?

Because Selectize's removeOption doesn't check for an array.
See: https://github.com/brianreavis/selectize.js/blob/master/src/selectize.js#L1196