OMEdit Visual glitches on high-res monitors

[ceraolo]

Today's 4k monitors in practice require fonts to be scaled-up. factors between 1.5x - 2.0x on DPI are typical.
Generally OMEdit behaves well in such environments, however:
1) the plus sign near variables in the Variables Browser is too large (First.png)
2) OMEdit about window is too small in comparison with font sizes (Second.png)
3) tools on the main toolbox are correctly scaled-up, while icons of views (icon, diagram, text, documentation) are too small (First.png).
In case it is deemed useful, I could add other items in the list in the near future.

The screenshots I add refers to 1.75x (i.e. 168 virtual DPI) in windows.