Implement new popovers

No issue

Implements a new popover component (not to be confused with what are now called dropdowns [menus])

Todo:

- [x] Emberify
- [x] Get checked over by people with Über Ember skilz

Rgr that, let's not forget :D

On Thu, Oct 16, 2014 at 9:50 AM, Paul Davis <notifications@github.com>
wrote:

> In core/client/templates/debug.hbs:
>
> > +                    <div class="popover-body">
> > +                        <p>
> > +                            <b>%t</b> - The title of your post (or page)<br>
> > +                            <b>%c</b> - The tag which your post is categorised in<br>
> > +                            <b>%y</b> - The year your post was published<br>
> > +                            <b>%m</b> - The month your post was published<br>
> > +                            <b>%d</b> - The day your post was published
> > +                        </p>
> > +                    </div>
> > +                {{/gh-popover}}
> > +            </div>
> > +            <br>
> > +            <br>
> > +            <br>
> > +            <br>
> > +            <br>
>
> There's nowhere that needs a popover right now, so this is just to preview
> and show its markup.
> Once the rest of the code is all good, I'll remove this & remove the [WIP]
> label.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/TryGhost/Ghost/pull/4213/files#r18964797>.
>