Issue 8 tweaks

Whole bunch of stuff that fixes everything else important in #13.

I've done it commit-by-commit so you can see.

With this version of karbon I've successfully got it running side-by-side with my MVC app with a single Layout file shared between them including site-wide menus served by Karbon and the homepage served by my existing app controller (but grabbing content from home.txt). It's awesome :)

cc @danieljanczak