+ XTEA helper type + see: http://en.wikipedia.org/wiki/XTEA
c'tor
Decrypt given ubyte array (length to be crypted must be 8 ubyte aligned)
Encrypt given ubyte array (length to be crypted must be 8 ubyte aligned)
See Implementation
+ XTEA helper type + see: http://en.wikipedia.org/wiki/XTEA