FakeToolTip: Enforce "no focus" policy on Windows

Evidently, it's not enough to call setFocusPolicy(), one also needs to
pass a special WindowType flag.

Fixes: QTCREATORBUG-4267
Change-Id: Ic2f377aad9a859443c79b375242bed2166301a3e
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

src/libs/utils/faketooltip.cpp

@@ -39,7 +39,7 @@
 namespace Utils {
 
 FakeToolTip::FakeToolTip(QWidget *parent) :
-    QWidget(parent, Qt::ToolTip | Qt::WindowStaysOnTopHint)
+    QWidget(parent, Qt::ToolTip | Qt::WindowStaysOnTopHint | Qt::WindowDoesNotAcceptFocus)
 {
     setFocusPolicy(Qt::NoFocus);
     setAttribute(Qt::WA_DeleteOnClose);