Refactor scripts into modules

This change is to convert existing JS scripts into modules and add a grunt build script to generate a bundle using browserify.

I need to perform more regression testing but I wanted to submit what I have so far to get some feedback.

Depends on https://github.com/vegphilly/vegphilly.com/pull/425.
I would also be open to removing it or keeping it since you can also use relative imports within the bundle like `require('./vendor_map')`. The only thing this really affects is how module names are externalized from the bundle.