Vertical Overview Support

[Doomsdayrs]

The Motivation

Users who use "Vertical Overview" will have a very wonky experience with windows (go test it yourself)

The Solution

Support the cube being vertical

[Schneegans]

Thanks for the suggestion!

This should be added. However, for me, other things will have a higher priority first. But if anybody volunteers in the meantime - it shouldn't be to hard to implement! This extension is still very small and easy to understand 😄

[Schneegans]

The extension has become much more complex in the last months. I think that it's not so easy anymore to port this to a vertical layout (and a vertical cube looks pretty weird anyways, I guess). Please refer to #71 for any further comments.