Bump version to v0.8.1-dev
Add more tests and refactor tests a bit
Add backported socketserver.py from Py3.3

This is needed to avoid sporadic test failures with http.server. (Not just on
travis-ci.org any more.) These have something to do with threading and Python
2.7 SocketServer.py using old-style classes.

The Python 3.3 socketserver.py is almost identical anyway to Python 2.7's
version. We force new-style classes, but otherwise it's pretty straightforward.
Actually add fix_apply to stage 1 (and fix its test)
Fix test exclusion on Py3.3
Try enabling http.server-related tests again on travis-ci (with backported socketserver)