Graph scale tweaks

[pde]

One person asked for percentages to always be shown on a 0-100 range and proportions on a 0-1 range. That might be worth trying, though we should also try some log or skewed version of that, allocating more vertical space as you get close to perfection.

Several people have asked us to make the Atari scale logarithmic.

We could implement this by having the scale objects affect the matplotlib axis properties.