Add image file processing to fully customize appinfo.json

[Torivon]

Right now, all graphics files must be manually added to appinfo.json. The goal is to be able to fully build the appinfo.json and make sure that it includes exactly the resources required. Art assets should be stored in src_data/images. There would be a file that includes all of the graphics needed for the base interface, which would then be combined with the resources listed in each story to build appinfo.json.

[Torivon]

This is now done and included in the basic process_stories.py. Any manual changes for appinfo.json need to now be made to base-appinfo.json, including version changes.