First pass at getting 1.8 working

There is work needed here, I need @mixonic, or anyone familiar with the new view layer, to take a look at:

```js
var temp = this.constructor.create({ context: context });
element.innerHTML = temp.createElement().element.innerHTML;
temp.destroy();
```

This is /not/ production quality code ;)  I just don't know of the best way of replacing the `renderToBuffer` logic.

Also, tests were failing quite extensively due to linting (even before I made any changes).  Once this PR is finalized, I'll lint the entire project and follow up in another PR to upgrade this to the latest version of ember-cli.
Likely you could just do that instead keeping all this logic. I don't think you need support for tagless views on this mixin, for example. And it confuses the intent of the code.