Add javascript formatter

[daveschaefer]

Eloquently put by JSLint - https://github.com/douglascrockford/JSLint:

The place to express yourself in programming is in the quality of your ideas and
the efficiency of their execution. .. Conforming to a consistent style improves
readability, and frees you to express yourself in ways that matter.

Rather than spending time discussing what formatting the code should be in, let's just hook up a javascript formatter and make it easy to use. All code that goes into the project can use it to keep the same look, saving time and making things consistent.

js-beatify can be run via python - https://github.com/beautify-web/js-beautify

Fantastic. Let's hook that up :)

[daveschaefer]

Note: this should happen after the 4.6.4 that fixes #59 . Unblocking signing and uploads is a much higher priority.