pg8000 passing test/orm/test_query.py
PEP8 tidy of test/orm/test_query.py
Remove requirement for manytomany_nonpassive

Removed the non_updating_cascade requirement from
test_manytomany_nonpassive. This is because setting
passive_updates=False in a relationship should work on *all* dialects.
PEP8 tidy for test/orm/test_naturalpks.py
Opened test_self_referential for pg8000

The test orm/test_froms.py test_self_referential works with pg8000 now,
so I've opened it up.
PEP8 tidy of test/orm/test_froms.py
Fixes for pg8000 for test/orm/test_dynamic.py
PEP8 tidy of test/orm/test_dynamic.py