Move the pages into the dialog class, needed to properly validate/invalidate the next button.

Also add a ApplicationInfo class to carry the new apps data to the plugin which still does the actual template extraction and creation of dirs..

Also changes the logic for the location a bit, the user now has to provide an empty or non-existing directory as location and the application name won't be added to that location. Application name and location on disk need to be completely separate.

Unfortunately this is somewhat broken right now (some paths are wrong when creating a project).