bin/git-rehash - generate stronger digests of content

should be better than
  "maybe I can just send the commitid to my timestamper
  to prove the content existed at that time,
  and hope the intended audience will still respect SHA1
  when I need that proof to stand up"


so why the modulino?
  http://www.nntp.perl.org/group/perl.module-authors/2013/09/msg10143.html
  It needs to be self-contained to work without a proper installer.
  Maybe later it will grow some tests.  Modules are easier to test.
  Maybe this code won't always live here.  CPAN is a nicer place.