Added QQuickItem to new class wizard

When creating a new class, you can select the "Base class" or "Type information"
QObject, QWidget, QDeclarativeItem... are available, but QQuickItem isn't..

Change-Id: I9fce6b6a43c915364fc405b99edd0b0d7ebab4fe
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>