Christmas update 🎄

### Bugfixes
* [x] Overlay now correctly fades out the `<footer>`-element
* [x] Links in galleries no longer have border on hover

### Changes 
* [x] Changed style of lines on `<blockquote>` and `<hr>`
* [x] Added styling for `<sup>` and `<mark>` *(from [Roon.io update](http://dev.ghost.org/ghost-0-5-6/))*
* [x] Cleaned up rich data. #29 *(Ghost added rich data natively)*
* [x] Added style for left/right hanging images and quotes. #31
* [x] Added `<cite>` to `<blockquote>` & `<q>`. #32