DLC Decryption

[onelight]

In r3436 I've added a new option for DLC. Since we still can't decrypt SPRX files without a PSP, I've added the ability to disable DLC decryption on JPCSP, which allows you to load decrypted DLC.
Unfortunately, there's no easy way to auto-detect if DLC is encrypted or not because the PSP always expect it to be encrypted. So, if you have DLC that contains SPRX files, you must decrypt them first with your PSP, place the decrypted content under JPCSP's PSP/GAME folder and check the option "Disable DLC decryption".

text r3469 and r3473
can load AKB149 DLC
still can not load God Eater 2 1.30 DLC