as discussed with luzpaz in https://github.com/FreeCAD/FreeCAD/pull/3735
there shouldn't be trailing newlines in translated strings.
- Moreover fix the logic of the output dialog text
* Support link and group objects
* Support view sync by implementing view provider API getMDIView()
* Use handleChangedPropertyType() for object migration instead of
reimplementing Restore() because of a lots of changes in
PropertyContainer::Restore().
* Various other small fixes.
- Page window is removed in two places. Problem with
display of 3D window when Page window closed was fixed
by http://github.com/FreeCAD/FreeCAD/commit/1d83d17.
This commit makes the code for Page object delete
consistent, but doesn't fix the problem with display
of 3D window.