Calculate MD5 of string. Different encodings possible. Taken from "Paj's Home" (Paul Johnston), under BSD license.
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/32982/216643/PajHome%20MD5.js
Original source: http://pajhome.org.uk/crypt/md5/md5.html
