- will call this 0.6

- will call this 0.6
- cleanup unused symbols in compat
- move any remaining conditional import switches out to compat
- pretty sure anything we use for a buffer will have flush()
- I can see that using the new io.* stuff means codecs isn't too
smooth here, but removed the double-wrap check in migration.py
which seems to be due to the bytesio setup in the test suite, simplified
this so that an encoding-writing test just writes to BytesIO
- removed all "from __future__ import with_statement"
- i think when we load_source(), that file might not be ascii
so we need to open as bytes
- make encoding an explcit argument in test suite write_script()
- sort the columns in autogenerate so that the autogen tests run
consistently on python3.3, seems to have a very random set ordering,
also loosen up an ordered check in test_op