1.6.0

• mount() now displays parsing and rendering errors in the diagram container. Invalid updates keep the last successful drawing dimmed, with the error shown along its bottom edge.
• Added Mounted.source and Mounted.error. Mounted.result is now undefined until a diagram renders successfully.
• onError now handles initial rendering failures and failed updates, in addition to automatic redraw failures.
• Mounted diagrams now receive unique SVG IDs by default, preventing conflicts between diagrams on the same page.
• Added --pele-error to customize the error text color.

API change: Parsing and rendering failures from mount() and update() are displayed in place instead of thrown. Use onError or Mounted.error to handle them.