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.
The purpose of `aliasmappings` is so you can write `require('vegancity/blah')` from any other module and it will work. You can also include modules by alias from HTML. Without this, you would have to refer to modules by their full path like this  `require('vegancity/js/src/blah')`. If that isn't a problem then we can remove `aliasMappings`.