Allow existing QtScript bindings to be usable by QML

A key point for QML is that you don't necessarily need to rewrite your logic parts to rewrite your UI with QML. This is not really possible with QtScript bindings, because you cannot access them through QML, so if you wrote your application logic for QtScript you will need some serious changes to use it in QML. Even though this means that you provided an imperative JS API, if it is imperative data tasks anyway they will likely be used in QML in about the same way.

Because this is trying to get normal , imperative, data logic, QtScript bindings usable from QML, it seems quite sufficient to allow the added JS bindings only in .js files imported to QML.