Initial work porting tex2jax to cheerio on the server.
Use custom, simplified implementation of tex2jax.

The previous commit used a modified version of the MathJax plugin
tex2jax that would run on the server, but this reimplements it using a
much-simplified algorithm.

The actual tex2jax supports custom delimiters around LaTeX math. This
still runs client-side when the page is loaded, allowing these
delimiters ($...$ and \(...\) for inline, $$...$$ and \[...\] for block)
to be used. This implementation requires you to use Markdown code blocks
(`inline` and ```<language>\n block \n```) for the LaTeX to be processed
when the page is generated. This runs Markdown, then searches through
the HTML for inline code blocks matching `\tex <math>` and blocks
matching ```tex\n <math>\n```. The "\tex " is removed; it signals that
the inline code is LaTeX. For blocks, the language "tex" signals the
preprocessor. The preprocessor replaces these with script tags with the
type attribute of "math/tex" or "math/tex; mode=display" for inline and
block math, respectively. Typogrify does not mess with things inside of
code or script tags.

This works well, with the only difference than normal MathJax being the
lack of a preview, which I will probably implement shortly.
Add a math preview span for every preprocessed block.
Use fenced TeX blocks in the nerf-gun-speed article.
Typogrify in tex2jax.testing.js and use my typogr fork.

The mainline typogr version will wrap ampersands in a span even inside a code block.
Add \degrees macro in the MathJax config file.

It expands to ^{\circ}, which is a superscript circle. I originally used
the Unicode codepoint for the degree symbol but it was barely visible.

Also, change double quotes to single quotes in the config file.
Add "When The Clock's Hands Line Up" article.

I've been working on this post for 24 hours now... I started last night
by trying to port the original tex2jax to node. I realized lying in bed
that I could just use custom delimiters (see 76e1e27) instead. Then this
morning I realized that typogr was wrapping ampersands inside script
tags with a span, so I forked that, fixed the issue, and sent a PR. Then
I finished writing my proof, edited it, and am finally ready to publish
it so many hours later.
Build.