New version of visibility switch undo compression
This patch is an alternative to !479 (closed)
The patch adds compression with the following characteristics:
- when the layer is the same and the property is the same, the undo commands are compressed
- when two undo steps revert each other, e.g. when the user toggles visibility on and off, then the two commands are annihilated, that is removed from the undo stack.
Testing Appimage package: https://yadi.sk/d/bWGePdvOVAQjfw
Edited by Dmitry Kazakov