Render the content of a specific block tag from a Django template. Works for arbitrary template inheritance, even if a block is defined in the child template but not in the parent. Generally it works like render_to_string from Django, but allows you to specify a block to render.

Features:

* Render a specific block from a template * Fully supports the Django templating engine * Partially supports the Jinja2 engine: it does not currently process the extends tag