Added jade-nim package

Jade templates (https://github.com/visionmedia/jade) are awesome for web development. It is a 'pythonesque' DSL designed specificly to generate HTML.

The jade-nim project is not a direct port of jade (that would have been too much work). It uses jade directly, and replaces the "compiled for client-side" javascript generation with Nimrod generation.

For short, you can now use Jade templates with Nimrod server-side too, because your jade templates are transformed into standard Nimrod procedures.