Disabling buttons: Undo, Redo, Delete objects when scribbling

[ollesmaps]

When in scribble mode I sometimes by accident Undo, Redo, Delete objects.

The look of icons for Undo, Redo in scribble mode - in downer toolbar is the same as look of icons for Undo, Redo of objects - in upper toolbar. That is why during work with my tablet I confuse buttons and involuntarily modify map.

I suggest the buttons of Undo, Redo, Delete objects are disabled in sribble mode.

Relates to #982.