upgrade express from 3.x to 4.x

I created this pull request for the review of the upgrade changes.
The hash style is one of the limitations of the package I'm using, [hamljs](https://github.com/visionmedia/haml.js/). This package is easily supported by npm, express, and consolidate.

An alternative package, which does support attribute style, is [haml-js](https://github.com/creationix/haml-js). Unfortunately I have had a difficult time trying to get this package to work and it appears to be less integrated into express.