updated the Jakefile.js jake build script and environment to support modern uglify-js (the API of that one has been changed; see also https://github.com/mishoo/UglifyJS2#the-simple-way and http://stackoverflow.com/questions/13919782/uglify-js-api-throws-typeerror-when-executing-example-from-github ); also make sure the ./build/ directory exists already from the very beginning: no surprises. Added package.json for `npm install` so you can load uglify-js and csso locally as they should.
update the package.json file: now points at the appropriate places.