Pixel tracking images.
Pixel tracking SVG.
Pixel tracking example: n.
Updated xcf file.
Put images in place.
Unescape some characters in script tags.
Show/hide steps.
Style figures.
Separate figures.
More or less finished draft of tracing pixels.
Changed the title again.
Another draft.
More complete version of tracing pixels draft.
Corrections.
Embed images in the article.

This is because IE doesn't support cross-file referencing in `use`
tags.

Also we had to put the SVG asset lib at the beginning of the article
because Safari has to have the element before we reference it.
Fix for FF and IE subpixel rendering.
Last draft of "Tracing pixels".