Revert "gui: added comment to indicate future improvement": it is not true

This reverts commit 2fde1ee87b74fe47693905c7cf544d5c9cddd5a8.

VisualSliderRange never has to care about units. It just displays and select values between a min and a max.

So this comment is wrong.
gui canvas: continue AngularResolvedCanvas so that it displays the images

not yet working... but at least there were more chances