• modified shasum to avoid file slurping (ref. sub sumfile)
  
• improved error handling of checksum files in shasum
  -- to better mimic the behavior of md5sum
  
• refined line-break regex in shasum (ref. sub sumfile)
  -- catches multiple CR's preceding LF
  thanks to Gisle Aas for suggested patch
  
• changed loop vars to signed int's in shadump (ref. src/sha.c)
  -- to prevent type mismatch warnings