- Should we be concerned about deserialize doing a string eval on the input,
   especially if that input came from some disk file they gave us in read()?

 - Make it work with 5.6.2.  Some issues:

    - namespace::clean and its dependencies have moved on, so older versions
      of each would have to be installed.

    - Crypt::Random::Source has "use 5.008" lines in numerous places.  I'm not
      convinced it really needs 5.8, but it won't currently build without it.

    - Math::Prime::Util has lots of issues with 5.6.2 on 64-bit machines, since
      5.6.2 can't represent integers in the range 2^50 to 2^64.  This version
      of Perl is just fundamentally broken and a _huge_ pain to work around.

 - There are, in my opinion, too many dependencies.  Installing this on a
   Cygwin system results in 49 dependencies installed, taking over a half hour.

 - The test suites do almost no failure testing.  Use Devel::Cover to see all
   the failure cases that aren't covered.

 - Look into allowing other SHA hashes for PSS and OAEP.

 - Decide if RIPEMD160 should be non-optional.  Module version 0.05 looks like
   it has an excellent test pass rate.

 - t/16-serialize.t is just verifying we don't die horribly.  We should verify
   that it's actually working.