Wrap onSelect callback in the Ember run loop

As described in the [Ember documentation](http://emberjs.com/guides/understanding-ember/run-loop/#toc_what-scenarios-will-require-me-to-understand-the-run-loop), non-Ember callbacks should be wrapped in the Ember run loop.
Merge pull request #2 from regularjack/patch-1

Wrap onSelect callback in the Ember run loop