UI style changes

**WIP**: Do *not* merge yet. Thanks :)

So this is quite a big set of UI style changes, they were all kind of linked so sorry for the big PR, but I did try to cut up my commits so you can more or less follow what I did. I'm still working on it, but wanted to put it up here now for folks to see. I should be "done" in a day or two (you're never really done with UI tweaks, but at some have to call "good enough" :p).

As I mentioned @jh-bate, this is really only CSS and layout, but there are a few things I'd like to point out to you. Don't have time to write it up now, but will come back and update this when I do.

I've put up a temporary demo version of these changes here:

http://demo-clamshell.nicolashery.com/

So you can navigate there on your iPhone, and make sure to "**Add to home screen**" for best experience :) Log in with whatever credentials, it doesn't matter in the demo.