Guide to decrypt EDAT files

Nothing particularly good... *sigh*

(On June 27th): [DH]'s computer broke once again and he might rewrite it from scratch on other machine.

Uh... backups? Or why didn't he just commit each days work to a separate branch on github like Nekotekina did with the SPU recompiler? Acts like a backup, if need be people can test on more games than his hard drive can ever carry, and it stops people from constantly asking for an eta...