QtIFW

Revert "Use QQmlV4Function to correctly get empty parameters from script."

This reverts commit eb574d77b0ab9a92b61e7738d089cd4ea4304e51.
The change will not work with Qt5.5 as it is causing constant
crashes in Qt installers. Using this change will require a fix
for Qt5. As we are about to make Qt installers based on 2.0 we
need to revert this change for now.

Change-Id: Ia7906d02db645f2407ab07d14f5a037224574b29
Reviewed-by: Andy Shaw <andy.shaw@theqtcompany.com>