Plot styling

[ketch]

Following up on our discussion about font sizes and such in plots: matplotlib supports custom styles, and we can define our own. It's a bit unclear how to distribute a style in a way that is easy for the user to automatically load, so it may be better to try one of the built-in styles. I have provided a few examples here:

https://gist.github.com/ketch/c9286ed82a016ae6e371ee6afae5d918

I think the plots with darker backgrounds and grids might be nice in some situations, but for now maybe 'seaborn-talk' is a nice minimal modification; it just makes the fonts larger.

If you try checking styles yourself, please note that you shouldn't run different cells in succession; the style changes are cumulative.