Resize stack, OSX= OK , Windows KO

[Sarah Reichelt]

> Result:
>                 • On Mac OSX : Stack and Sub-Stacks resizes OK.
>
>                 • On "Windows" :        • I can resize the Stack
>                                                 • I Can't resize the sub-stacks (Arrows are not appearing).
>

In Windows, the decorations of a stack have to be set to default to
allow resizing.

Sarah