zeroconf: port to Python 3 Since we're using the source transformer on Python 3, calls into Zeroconf and return values from it are generally bytes. But various socket functions require str on Python 3. This commit contains enough changes to coerce test-paths.t into passing on Python 3. I suspect there are still a handful of bugs on Python 3. But the tests do pass. Differential Revision: https://phab.mercurial-scm.org/D5805