Subpackage dialog added pages (2,3,4,5,7) validations

From state diagram I forgot about dialog for adding subpackages. Now it's there and also works validation of 2,3,4,5,7 pages of wizard. There is an output of 'tags' and 'scripts' those are saved in Base() classes object after switching from "Build page" to "Finish page". There is also a filter on 2nd page of wizard for importing sources (file dialog) - now user can choose only dir.