Update Digest-SHA to CPAN version 5.92

Update Digest-SHA to CPAN version 5.92

  [DELTA]

5.92  Sun Jun  1 00:15:44 MST 2014
  - fixed reserved-word clash when compiling with C++
    -- use 'classname' instead of 'class'
      -- ref. SHA.xs (rt.cpan.org #96090)
  - silenced MSC compiler warning about signed/unsigned comparison
    -- ref. SHA.xs (rt.cpan.org #95830)

5.91  Fri May 16 10:21:44 MST 2014
  - restored original 'addfile' for use on opened file handles
    -- allows callbacks in place of actual files
      -- ref. IO::Callback (rt.cpan.org #95643)
  - re-established inheritance from Digest::base
    -- to pick up future Digest enhancements automatically
  - cleaned up documentation

5.90  Wed May  7 07:57:08 MST 2014
  - consolidated all dynamic memory allocation into XSUBs
    -- streamlines referencing of SHA objects
    -- simplifies DESTROYing of objects
  - enhanced Makefile.PL to allow 'use warnings'
    -- automatically reverts to $^W for early Perls
  - scrubbed C and Perl code to remove all compiler warnings

5.89  Sat Apr 19 05:14:48 MST 2014
  - added universal newlines mode ("U") to addfile and shasum
    -- based on Python Universal Newlines concept
      -- newlines identical across MacOS, DOS, and UNIX
    -- will deprecate portable mode ("p") in future
      -- "U" mode is cleaner and more efficient
  - enhanced performance
    -- reduced number of dynamic memory allocations
    -- sped up addfile method with use of C code
      -- ref. SHA.xs (_addfilebin and _addfileuniv)
  - eliminated experimental -M option in favor of new -R option
    -- reverses order of digest module preference
    -- undocumented: for test and development use only
  - sealed memory leak in SHA.xs
    -- arose only with SvPVbyte exceptions during eval
  - patched inheritence bug (ref: rt.cpan.org #94830)
    -- use sv_isobject/sv_derived_from instead of sv_isa
  - added 'allocated' flag to SHA structure (ref. src/sha.h)
    -- to guard against Perl double frees