all: Finalise python3 support.
Basically, wrap stdout and stderr whenever they do not have an encoding with an ascii-encoding writer, and write unicode to stdout & stderr. wsgi.errors is defined in the reference implementation as being a StringIO, so follow that. Stop using argparse.FileType to get rid of python3 "file not closed" errors. Also, fix setup access to CHANGES.txt . Also, fix 2to3 involvement. Also, replace test.captureStdout with extra tool arguments.