Issue #14814: Remove redundant property from interface objects - prefixlen can be accessed via the associated network object

Issue 14814: Docs work showed some more cases of networks pretending to be addresses and highlighted the weird approach to implementing the 'is_whatever' properties. Impl now illustrates far more clearly that networks have a property if both their network and broadcast addresses have that property

Close #15559: Implementing __index__ creates a nasty interaction with the bytes constructor. At least for 3.3, ipaddress objects must now be explicitly converted with int() and thus can't be passed directly to the hex() builtin.

Patch by Roger Serwy.

Patch by Roger Serwy.

os.sched_setaffinity now use regular sets of integers to represent the
CPUs a process is restricted to.

asynchat speedup improvement: avoid to use a function mimicking old buffer() builtin behavior; instead use plain slicing

sys.stdout and sys.stderr are now using "\r\n" newline on Windows, as Python 2.

sys.stdout and sys.stderr are now using "\r\n" newline on Windows, as Python 2.

doesn't translate newlines on output.

translate newlines on output.

Make TextIOWrapper's documentation clearer by copying the newline argument's description from open().

Make TextIOWrapper's documentation clearer by copying the newline argument's description from open().

Replace _s with ptr to avoid future confusion. Add also non regression tests.

Patch by Philipp Hagemeister.

Patch by Philipp Hagemeister.

Issue #15502: Bring the importlib.PathFinder docs and docstring more in line with the new import system documentation, and fix various parts of the new docs that weren't quite right given PEP 420 or were otherwise a bit misleading. Also note the key terminology problem still being discussed in the issue