Remove __author__, __credits__ and __copyright__ from stdlib modules

Around twenty stdlib modules, including json, io, inspect, and tarfile, still set __author__, __credits__ or __copyright__ attributes, mostly left over from when the modules were first added. $ git grep -E "__(author|credits|copyright)__" Lib/bz2.py:__author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>" Lib/concurrent/futures/__init__.py:__author__ = 'Brian Quinlan (brian@sweetapp.com)' Lib/concurrent/futures/__init__.py: return __all__ + ['__author__', '__doc__'] Lib/concurrent/futures/_base....