[ENHANCEMENTS]
- Added support for HARNESS_OK_SLOW. This will make a significant
speedup for slower connections.
- Folded in some changes from bleadperl that spiff up the
failure reports.
[INTERNALS]
- Added some isa_ok() checks to the tests.
- All Test::Harness* modules are used by use_ok()
- Fixed the prototype for the canonfailed() function, not that
it matters since it's never called without parens.