Changed

This release is a major refactoring of the program.

• The --map-id and --map-class options have been removed, replaced with a new (more general) -a/--attribute option.
• The --hidden and --offscreen flags have been mooted; maps always contain style="display:none" now.
• SVG content warnings are now more specific.
• Map tags are now printed one per line (instead of all being jammed into one).
• Errors are now emitted if a source image contains scripts, an offset viewbox, or repeated IDs.
• Performance is ~10x faster.
• Known SVG attributes and tags now have their cased normalized, e.g. <SVG> -> <svg>.
• Symbol IDs and aspect ratios are now printed to STDERR for reference.