1.0.4    2006 January 24
         Added a clone() method that clones the state of the current object and
         returns the cloned object.

         add and addfile now return current the object so ->add( "foo" )->digest
         works like it does in other digest modules.

         Added a b64digest method that is an alias for the base64digest method.

         Removed (add addfile reset) from @EXPORT_OK, 

         Updated the LICENSE section to the recommended FSF GPL notice

         b64digest no longer returns a trailing ==

1.0.3    2004 August 18
         Modified hashsize() to return number of bits, instead of bytes
         (to become consistent with Digest::SHA of Mark Shelor)

1.0.2    2003 July 29
         Minor code cleanup

1.0.1    Optimized even more
         Refined "files.pl" example script by including error-checking

1.0.0    2003 June 07
         Initial release