Revision control

++ Qt 6.0.0 is a new major version release of Qt. It is not binary compatible with
++ earlier Qt releases.
++
++ The goal has been to retain as much source compatibility with Qt 5.15 as
++ possible, but some changes were inevitable to make Qt a better framework.
++
++ To make it easier to port to Qt 6.0, we have created a porting guide to
++ summarize those changes and provide guidance to handle them. In the guide, you
++ can find links to articles about changes that may affect your application and
++ help you transition from Qt 5.15 to Qt 6.0:
++
++
++ For more details refer to the online documentation of Qt 6.0:
++
++