Add "mistune" for Markdown

[smnslwl]

No description provided.

[geekan]

What's the difference among the python-markdown projects?

[smnslwl]

Well the most popular implementations of Markdown parsers in pure Python are Markdown, Markdown2 and mistune, and mistune seems to be the fastest of the lot.

[geekan]

From this link: lepture/mistune#1
It points out Misaka is the fastest one.

Parsing the Markdown Syntax document 1000 times...
Mistune: 12.9425s
Misaka: 0.537176s
Markdown: 47.7091s
Markdown2: 80.5163s
cMarkdown: 0.680664s

What's the profit of implementing via pure Python?

[smnslwl]

Well, pure Python libraries are far more easier to install than ones that are interfaces/bindings to C libraries. One may not always be able to install the underlying libraries, for example if you do not have root access to a machine. I think mistune strikes a happy balance between speed and ease of use.

[geekan]

Looks good. Merge now.