Pyro5

- improved and cleaned up exception handling throughout the code base
- URIs now accept spaces in the location part. This is useful for unix domain sockets.

Anaconda pyro5 package has been added to conda-forge

- made the decision that Pyro5 will require Python 3.5 or newer, and won’t support Python 2.7 (which will be EOL in january 2020)
- begun making Pyro5 specific documentation instead of referring to Pyro4
- tox tests now include Python 3.8 as well (because 3.8 beta was released recently)
- dropped support for Python 3.4 (which has reached end-of-life status). Supported Python versions are now 2.7, and 3.5 or newer. (the life cycle status of the Python versions can be seen here https://devguide.python.org/#status-of-python-branches)
- code cleanups, removing some old compatibility stuff etc.

various things ported over from recent Pyro4 changes:

- added a few more methods to the 'private' list
- fix thread server worker thread name
- on windows, the threaded server can now also be stopped with ctrl-c (sigint)
- NATPORT behavior fix when 0
- sdist archive is more complete now
- small fix for cython

- travis CI python3.7 improvements
- serialization improvements/fixes
- reintroduced config object to make a possibility for a non-static (non-global) pyro configuration

- python 3.5 or newer is now required
- socketutil module tweaks and cleanups
- added a bunch of tests, taken from pyro4 mostly, for the socketutil module
- moved to declarative setup.cfg rather than in setup.py
- made sure the license is included in the distribution