Fix buffer initialization size in IT loader

Fix initialization bug reported by Jacques Philippe:

from:	 Jacques Philippe <jackp@wanadoo.fr>
date:	 Wed, May 15, 2013 at 6:25 AM

it_load.c, line 257, inst_map is declared as int[120] but later, line 577
i find for(j=0; j<XMP_MAX_KEYS; j++)...

As XMP_MAX_KEYS is = 121 it will crash. (same at line 688)

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Update changelog

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Replace MD5 code with a public domain version

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Remove decryption code from Powerpack depacker

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>