Pylogram cartoons, now with captions

Cartoons, now with added captions!

The wonky edges of the panels I think are because I used floats
instead of Fractions to see if it was any faster; I think that was a
mistake and I need to switch back.

Source for the cartoon:
https://github.com/CartesianDaemon/pylogram/blob/master/example_cartoonstrip.py