A fast, small, compliant Markdown parser implementation

MD4C is Markdown parser implementation in C, with the following features:

* **Compliance:** Generally, MD4C aims to be compliant to the latest version of
  [CommonMark specification](http://spec.commonmark.org/).

* **Performance:** MD4C is [very fast](https://talk.commonmark.org/t/2520).

* **Compactness:** MD4C parser is implemented in one source file and one header
  file. There are no dependencies other than standard C library.

* **Portability:** MD4C builds and works on Windows and POSIX-compliant OSes.
  (It should be simple to make it run also on most other platforms, at least as
  long as the platform provides C standard library, including a heap memory
  management.)

* **Permissive license:** MD4C is available under the MIT license.

## lila patches

I wote a few patches to tweak a bit how emphasis works. Each patch provides a
new extension that can optionaly be enabled (at runtime, like existing
extensions) :

* ITALIC : To enable `/italic/` support
* BOLD : To enable `*bold*` support
* BOX : To create some "box" blocks, for e.g. warnings, etc
* HIGHLIGHT : To enable `=highlight=` support
* INDENT : To enable indented block support

You can of course see all of them in use in [qmdoc].

[qmdoc]: http://lila.oss/qmdoc