        A brief description of the password format:
        First, the 24 6-bit characters of the password string
        are converted to 18 8-bit values. 


	The last (18th) byte
        is the password checksum. It's the lowest byte of the
        sum of the 16 first bytes of the (decrypted) password.


        The 17th byte is the decryption value, which is the
        number of times to rotate the password data (the first
        16 bytes) left.

	Note that the bits are rotated from one
        byte to another (not just within the same byte), so the
        password data should be treated as one big 128-bit value.
        Once the password has been decrypted, the checksum is
        recalculated and is compared to the original checksum.
        If the two values match, the game will proceed to load,
        and acknowledge the password data.




