||The main class for the Skein hash algorithm by Niels Ferguson,
Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno,
Jon Callas and Jesse Walker.
||Calculates the tweak values according to the various tweak fields.
||SkeinMain is used to test the SimpleSkein, UBI64 and Threefish implementations and to see that the test vectors, including initial chaining
vectors are correct.
||Implementation of the UBI function that can be used to chain the three parts of the Skein hash algorithm together.
||Some utilities and constants that may be usefull.