Syntax changes in server.js, lib/mkdir-p and node-nailer. Removed vendor dir. Added node_modules dir, including a manual modification to imagemagick.js.

Ian created a pull request for node-imagemagick to fix a particular problem: https://github.com/ianblenke/node-imagemagick/commit/d989d75980f65e544ad32c7d74f6cbbf85f52119. Until it gets properly merged, I have performed `npm install`, made the modification, and included it in the commit. In the future, we should not include the contents of `npm install`.