MaskEditorToolpanel now using DoubleSpinBox (#869...)

More to follow on #869 (closed)...

added 2 commits

• 9c52053c - MaskItems: don't emit signal maskGeometryChanged() => broken
• 5892a7d3 - restore some signals, now in MaskGraphicsScene

Compare with previous version

enabled an automatic merge when the pipeline for 5892a7d3 succeeds

merged

mentioned in commit ebda86e5