QtSupport: Add missing Q_OBJECT macro

Without it this QObject is not accessible from Javascript
as it needs to be.

Change-Id: I6ffdb677cc3c986f0f95bded60f6f097b2c4f3cd
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
QtSupport: Code cosmetics

Avoid one needless level of nesting.

Change-Id: Ied229d59eef03493041fe9e802ec71ca6e40e0a6
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
QtSupport: Add method to query UI class name

Change-Id: Idc1cfd87415093dab4245d84797b0971ec496b45
Reviewed-by: Daniel Teske <daniel.teske@digia.com>