Line styles: double/triple lines

[Bug Importer]

In the line styles dialog, there is a long list of dotted and dashed line
types. However, all lines appear to be single lines. It would be nice to
have a list of single, double, and triple line styles as an independent
option.

For example, the list might contain
- single line
- double lines, both equal
- double lines, medium-thin
- double lines, thin-medium
- double lines, thick-thin
- double lines, thin-thick
- triple lines, all equal
- triple lines, thin-thick-thin
- triple lines, thick-thin-thick
- triple lines, thin-medium-thick
- triple lines, thick-medium-thin

The line thickness would determine the total width of the combined lines.
The thick-medium-thin would be in a fixed proportion such as 3:2:1.

The dash and dot options would obviously apply to the combined line, so
that whitespace separating dashes or dots would apply to all strands of a
line.

[Stephen MᶜAteer (s-g-mcateer)]

I would like to add my voice to this feature request.