Mistletoe

**Features**:
* auto-closes unclosed code fences;
* adds support for "[footnote]"-style links;
* interactive mode adds keyboard control support;
* accepts multiple filenames from the command line.

**Fixed**:

* `render_image` function missing argument;
* mistletoe crashes with empty list items;
* removes redundant whitespace for empty lines in code fences;
* fixed performance issues on PyPy: very, *very* fast now.

**Features**:

* span-level token constructors now accept match objects;
* simplified adding custom tokens to the parsing process;
* simplified creating new renderer classes.

**Development**:

* refactored (most of the) tests;
* cleaned up benchmarking script;
* cleaned up some spaghetti in tokenizer modules.

**Features**:

* added table-of-contents plugin;
* added rudimentary MathJax support in mathjax plugin;

**Fixed**:

* mistletoe crashes with text between underscores;
* incorrect handling of hashes in code blocks;

Relicensed under MIT.

**Features**:
* added support for footnote-style images and links;
* added support for LaTeX renderer;
* renderer classes are now context managers (see README).

**Development**:
* added test suite for LaTeX renderer;
* added benchmarking script for performance comparison;
* added scripts to compare render output across commits;
* added CI testing for versions up to Python 3.3.

**Fixed**:
* a bunch of regex craziness;
* outdated documentation.

This release is mainly to celebrate that I shaved. Other than that:

**Block-level token support**:

* heading (ATX and setext);
* quote;
* paragraph;
* block code (code fence and indented code);
* lists and nested lists;
* tables;
* horizontal rule;

**Span-level token support**:

* strong (with asterisks or underscore);
* emphasis (with asterisks or underscore);
* inline code;
* strikethrough;
* images (inline link only);
* links (inline link only) and autolinks;

**Output format support**:

* render to HTML;
* render to [mdast](https://github.com/syntax-tree/mdast)-like AST;
* render to really janky LaTeX;

Lastly, hello world!