Port utils to Python 3
Port daf_base to Python 3
Port pex_policy to Python 3
Port pex_config to Python 3
Port afw to Python 3
Adapt daf_butlerUtils to py3
Adapt skypix to py3
This has few dependencies, so I can do it before pipe_*.
Simon or Tim, can you please review this? monocam doesn't have any tests, so I'm not sure how to check that I broke anything. Also, I accidentally pushed the pep8 cleanups to master.
Looks good. One minor comment on PR regarding `map()` versus a list comprehension/generator type thing. I really don't think `map()` looks at all pythonic.
Thanks for the iterator suggestion, Tim Jenness. There are no tests, but a full demo test including obs_monocam passed, so we can assume nothing is new is broken.