mojombo/jekyll — pull request #1066 by Rowno (2013-05-09 10:15:43+00:00)
Title: Add a `data-language` attribute to code blocks

Allows a language label to be added to code blocks using a CSS pseudo-element. It would also make it easier to retrieve the language using Javascript, rather than having to parse the classes.

Example:
```css
code:before {
content: attr(data-language);
}
```