Added a bit to the EXT[124] tests, and refactored them to squash code duplication.  Note that these still don't get run under cPickle.
Added a bit to the EXT[124] tests, and refactored them to squash code
duplication.  Note that these still don't get run under cPickle.

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