HG-89: Implement lightbox

This is a work in progress:

**TODOs**
- [ ] Select lightbox component
- [ ] Integrate the component
- [ ] Check edge cases (no images, videos, galleries)
- [ ] Profit

how about reopening View class and adding this to it
http://mavilein.github.io/javascript/2013/08/01/Ember-JS-After-Render-Event/