Add a warning message when a WM_DESTROY not triggered by Qt is received.

Task-number: QTBUG-34503

Change-Id: I7a1e06b34deaf8e595f4986114701480bdcf219c
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Windows: Do not set transient parent on popups.

Analoguous to Window creation code.

Task-number: QTBUG-34503

Change-Id: I3cf7d58999bff5b106ca9d2e2c6f550e35f9db9a
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>