New rules for perl5/Exporter

The Test::* modules get added as required dependencies, which end up
in the runtime list, not test.  This is turning into a widespread
problem with CPAN code (people are VERY sloppy with dependency specs,
since they are almost always manually managed).  We may need a generic
test to catch these.  I am trying to avoid having to publish things
like Test::Exception to the production environment, or bundle them for
local installation.