Build 3.5.0.118 of xlsgen adds support for shape groups from XLSX files.

Shape groups are the result of shift-clicking more than one shape in Excel and clicking Group in the Format ribbon. Shapes in question can be anything among charts, text boxes, vector shapes, pictures, ...

Internally those are saved a lit oddly and xlsgen would just ignore them so far, unfortunately ignoring the actual shapes as well.

Obviously, there can also be groups within groups. So this was also a scenario to support.

xlsgen correctly reads shape groups and use them for rendering, inspecting and copying purposes.