Switch to ember cli

Although we haven't had any issues with the existing build system, there looks to be many advantages to jumping on ember cli as it basically improves upon everything we were trying to accomplish on our own and potentially will have problems we haven't hit solved.

This also switches from mocha + chai for testing over to qunit. The benefit here is purely to open up the usage of all the advancements to ember testing without waiting for the isolated containers and helpers to be made framework agnostic.