The 128 bit MD5 hash is converted into a 32 character long String.
Each character of the String is the hexadecimal representation of 4 bits
of the digest.
author: Remy Maucherat version: $Revision: 1.2 $ $Date: 2001/07/22 20:25:13 $
Encodes the 128 bit (16 bytes) MD5 into a 32 character String.
Parameters: binaryData - Array containing the digest Encoded MD5, or null if encoding failed