[DUPE] Viewer: Multiple image display: Allow different Zooms

[ubacher]

In IM3's Side-by-side window one could have different zoom levels for each image.
This is useful when comparing "identical" images of different dimensions.

The request is for IM5 to also allow zooming  displays individually.

[ubacher]

This is the same request as already made by Gerd in Topic 612.