Support to ember-engines

Hi @chriseppstein I'm working o roadmap to ember-engines 1.0. I just don't understand how this does not work with ember-engines, and Linkedin uses ember-engines on its main site. Maybe it's a workaround, I don't know

But I would help on anything to make this able of running with ember engines.

thanks!

Start by clarifying which ember-engines behavior is incompatible and how LinkedIn's main site currently works with it. No files, tests, or entry points are named; done would mean a defined compatibility change and evidence that css-blocks runs with ember-engines.

Written by the indexing model from the issue text.