Add pretty loading/rendering screens

[kittsville]

I'm thinking take a bunch of the stuff I did for Actypus and use it on Pyroon's front-end. This would involve a loading screen for assets and a screen while the browser renders the Cytoscape graph.

This would serve two purposes:

• Faster loading times (various Google recommended optimizations)
• Users don't just see a janky Time New Roman "Loading" in the top left*

*Which doesn't give me much faith in the site loading and I made the damn thing

[kittsville]

Check fancy-front branch for progress

[kittsville]

Loading the site via Chrome's throttling tools shows horrific performance over slower connections. I got Actypus loading in fractions of a second. Those synchronous scripts are ruining page loads! Will need to wrap Cytoscape/etc. in wrapper functions so they can be loaded async.

[kittsville]

Wrapping covered in #13.