Import all implementations of the hash algorithms (OpenSSL & builtin) and run the test suite across all that are available.  Warns about extension modules that could not be imported when python was compiled with Py_DEBUG.
Import all implementations of the hash algorithms (OpenSSL & builtin) and run
the test suite across all that are available.  Warns about extension modules
that could not be imported when python was compiled with Py_DEBUG.

That warning could be made fatal but I didn't want to do that initially as
I suspect non setup.py based build processes (windows, any others?) won't
compile them all conditionally based on the Py_DEBUG setting today.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator