Also adds an Illustrator script that automatically
handles all of the tracing

Outlines are expensive to render, since they require a blur of
a drop shadow. They're still available, but the default is
now to just brighten them and turn them sepia

This turns into horizontal scroll input, so we just
use deltaX when shift is held.

This mostly helps with mobile Safari

Drawing an SVGImageElement to a canvas goes haywire. This checks for
that behavior and warns about it, and turns off the fine-grained
selection logic.

This fixes the ultra-fast scrolling that was happening in Safari.
It also makes scrolling more consistent in general.

I forgot to undo some changes to the drawImage logic oops

The click-test code skips the pixel test in Safari, since
drawing SVGs to a canvas is, apparently, a buggy mess.
This also adds a bunch of -webkit-user-select properties
to make things unselectable in Safari.

This adds a CR1632 button cell

Some event listeners were being set up instantly, rather than
after the document was fully loaded. This caused them to try
to access a canvas before it was ready, spitting out an error.
The relevant code is now in the DOMContentLoaded block.