visionmedia/jade — pull request #600 by chowey (2012-04-22 13:00:54+00:00)
Title: Make mixin blocks act like blocks

This removes the `contents` keyword, and adds the `block` keyword:

* `contents` was a string, is now removed

* `block` is a function, is called whenever the `block` statement is used within a mixin

* Because `block` is a function, it is called "in-context" and can therefore render prettily

* `block` can be tested for truthy-ness, e.g. `if (block)` works as expected