Port Qt.include() over to v4

Still doesn't quite work as it should, but that's no regression to
before neither. The reason is that the context handling is still v8
based and needs to be rewritten.

Change-Id: I51216f93d6db4ba26f8adddaeb39d8a8c62df7ee
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>