Previously they were leaked when a qmldump or the C++ exported QML
type list updated.
Just deleting the previous FakeMetaObjects is not an option, as they
might still be used in a QmlObjectValue owned by an Engine.
Reviewed-by: Erik Verbruggen
If there's a library.xml file next to the qmldir file, Creator will
read that instead of trying to run qmldump on the library.
Reviewed-by: Erik Verbruggen
