Stabilize tst_qquickitem.
Stabilize tst_qquickitem.

Instantiate windows and views on the stack or add
QScopedPointer. Add waitForWindowExposed() after show().
Add diagnostic message.

Task-number: QTBUG-32664
Change-Id: I190f2a0490b8333a7886a23e26582c6cb615df94
Reviewed-by: Simo Fält <b598cfbc9cb80e3067479e5abd365cdf44c9b327@digia.com>
Reviewed-by: Sergio Ahumada <27ca633ce817d1c3858ceeac3c99febb78411853@digia.com>

qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d