Support for different versions of QtQuick

With QtQuick 1.1 we'll have to support different versions of QtQuick / different namespaces in QtCreator.

Qml-related Wizards

The wizards should be able to put different namespaces in the generated code. This could be on basis of a 'target' Qt version that needs to be specified per project, or on an explicit setting in the wizard.

QuickDesigner

QuickDesigner should be able to handle different versions of the QtQuick namespace gracefully. Depending on the target Qt/QtQuick version, and the existing namespaces in the .qml file the library and the property editor should be adjusted.