Page Hopper Component

Initiated using `cmd`/`ctrl`+`k`.

Edit: Now 100% prettier:

![lp-page-hopper](https://cloud.githubusercontent.com/assets/708296/3641571/865efcea-10b5-11e4-8eb9-7cc021244b35.gif)


This isn't quite right I don't think.

Lightbox is listening to `:flyout/close` which I thought had been agreed was a bad idea and led to a bunch of confusion with toggleActive/Flyout/Lightbox. Shouldn't this be listening to `:lightbox/close` (fired by flyout) and then anything else could hook into it when necessary?