Base32hex -> hexadecimal string decoder
Base32hex is a base32 variant using different alphabet, that is "0123456789ABCDEFGHIJKLMNOPQRSTUV". This allows easily sort base32hex string in a same way as binary input would be sorted. On the other side this alphabet contains (contrary to base32) easy to mix character pairs: 0 and O, 1 and L, B and 8.