Squash 1:1 nested rings

[joscha]

Add option to de-duplicate rings that don't convey information.

If you look at: https://aui-cdn.atlassian.com/atlaskit/pr/stats/e50623ba0ad8b839ba1ebce33cfd49d507823f01/ak-editor-toolbar-hyperlink/cjs.html

You can see a few rings that only represent folders. Each folder only has one subfolder, so the nesting is very deep, but there is no new information added or branching conveyed. It would be great if these rings could be squashed, so the output becomes more meaningful.