Add mobile support and Reddit 404 image

There are three separate commits in here.

The first is cherrypicked from changes made when my editor automatically removed whitespace on save.

The second adds mobile support -- essentially adding a meta viewport tag and changing a height or two to min-height in the CSS. Additionally, I changed the number entries from <ul><li> to <div>s for easier styling.

The last commit gets a 404 image from Reddit each time the page is loaded. The code can be modified to keep trying upon http errors, but I don't suggest doing that because that could potentially infinite loop you (if Reddit is returning 404s/403s/etc), or slow down the loading of the page immensely (429 rate limit requests). 

Here's a before/after of the mobile changes:

![Before](https://cloud.githubusercontent.com/assets/6532435/3350685/4e519044-f9ca-11e3-88c0-5c3984955c72.png)

![After](https://cloud.githubusercontent.com/assets/6532435/3350687/6d845a0a-f9ca-11e3-9b66-178263032cae.png)