Add a title, description, and dependency/code climate badges.

Add application title and a (very) short description.
Fix environment-specific settings.

These stopped working once we moved to a modular Sinatra app
because `development?` is no longer available. We need to
use `settings.development?` instead.
Convert to the HAML template engine.

As we add more pages and supported websites, I'm afraid that the main
Ktty file is going to become unreadable. Plus, I really just want an
excuse to try out HAML.
Use Sinatra AssetPack to compress CSS.

As part of this transition, I swapped from SASS back to regular CSS.
I was having trouble getting AssetPack to compile it correctly, and
we weren't using it for anything useful anyway.
Completely overhaul the asset pipeline.

I've started using Sprockets to combine CSS and JS files. It's a lot
more mature and robust than Sinatra Asset Pack, which wasn't working
correctly anyway.

Language dependencies and extensions are now handed by Sprockets
bundles instead of the main Ktty class. There's a little more overhead
upfront but less overhead while processing page requests.

Prism is now a git submodule instead of manually copied files.