Npm improvements

[nomorepanic]

Packaging and building improvements:

• Adds a package.json file that can be used to install dependencies
• Uses grunt to build files instead of build.js
• Add a .gitignore files and remove node_modules from the repository, since package.json can fetch dependencies now

If the changes are too intrusive, you can use parts of them or pick single commits.

[coatsnmore]

+1 for package.json