Add support for subfolders in roms

Issue #11 on hold
Eric Bole-Feysot
repo owner created an issue

Usage of progettosnaps dat are not possible in current version because of this missing feature.

Ex: snapshots dat here http://www.progettosnaps.net

progettosnaps contains one game with a lot of roms in subfolders. Subfolders are not currently supported in rc4.