Move ALL opponents (except the re-skins) into opponents/. Include all opponents in listing.xml, giving unofficial opponents status attributes.

Official and testing opponents are included in deployment by way of a python script. Only official opponents will be included on the individual select screen, unless additional status classes are listed in config.xml (e.g. <include-status>offline</include-status><include-status>testing</include-status>).

This simplifies status changes since directories don't have to be moved around and we don't have to specify full paths in listing.xml. It also simplifies code since we don't have to extract the opponent id from the folder path.

Unlocked epilogues will also work with offline/incomplete opponents, and stay unlocked if/when those are moved to official status.