ToUUID byte order fix

The expected bytes for UUID "{e4178468-df95-44d0-ad87-f22a5d5fb6d3}" are
   68 84 17 E4 95 DF D0 44 AD 87 F2 2A 5D 5F B6 D3

The serialized chars are
   b6d3 5d5f f22a ad87 44d0 df95 8468 e417