Add Non-linear Fitting

Added a non-linear fitting notebook that fits some kinetics data of
mine.
Extracted styling and SMC fixes

I extracted some of the styling information into a separate Python file.
This includes loading a custom style sheet. We'll see how this does on
SMC.

Went through the other notebooks and fixed some small things. The
Basemap example needed a lot of fixing, because SMC doesn't allow
external network access.