Convert docstrings to comments for nose; PEP8 cleanup (some tests activated)

@charris -- hmm, have to be more careful what I volunteer for next time ;-) Anyway, no more docstrings in `ma.tests` and nothing pink in my emacs window. In the process, discovered that a few cases where I was warned that a variable was assigned to, it implied that a test did not actually run correctly. For one of those cases, what is tested actually fails (I'll add a line note).