Highlight overlapping lines

[tordans]

Usecase: I prepare SVG for laser cutting. One important step is, to make sure no line is cuttet twice, so no line overlaps another line.

Feature Request: It would be awesome to have some visual clue in the highlighting of the tool that shows overlapping lines. Those could be of two types: a) identical lines that are in the doc twice (copy-paste or auto-generation errors), b) one line is shorter but overlaps the other line fully or in parts.

Apart form the laser cutting usecase this check would help optimizing an svg for web as well.

[winkerVSbecks]

@tordans could you share some sample SVGs that simulate this issue?