Problem: Some key+modifier tests fail on some AppVeyor images.
Solution: Adjust the tests for key movements and fix the revealed bugs.
(Christopher Plewright, closes#11798)
Problem: MS-Windows: various special keys and modifiers are not mappable.
Solution: Adjust the handling of keys with modifiers. (Christian Plewright,
closes#11768)
Problem: Code handling low level MS-Windows events cannot be tested.
Solution: Add test_mswin_event() and tests using it. (Christopher Plewright,
closes#11622)