Adapt CFC Perl build for CPAN dist compat.

The CFC build process has to work properly in both the repo layout and
the layout of a CPAN dist.
Add a `dist` action for CPAN to CFC Perl build.
Make runtime Perl build work with CPAN layout.

Correct some incompatibilities which assumed the repo layout.

Consolidate code which changes behavior for CPAN layouts inside the
module, leaving Build.PL with only straightforward arguments.
Add a `dist` action for the runtime's Perl build.
Prep Clownfish::CFC for independent CPAN dist.

Flesh out prerequisites and other dist metadata.
Update runtime Build.PL prereq, abstract.

Make Clownfish::CFC a CPAN prereq for Clownfish.  Use "Apache Clownfish"
rather than "Clownfish" in dist abstract.
Add MANIFEST.SKIP for CFC Perl build.
Make Storable failures graceful.

Throw exceptions rather than segfault when Clownfish objects are
serialized using Storable.