SF patch# 1770008 by Christian Heimes (plus some extras).
Completely get rid of StringIO.py and cStringIO.c.
I had to fix a few tests and modules beyond what Christian did, and
invent a few conventions. E.g. in elementtree, I chose to
write/return Unicode strings whe no encoding is given, but bytes when
an explicit encoding is given. Also mimetools was made to always
assume binary files.
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index a1ab0f1..4710c8c 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -1685,8 +1685,8 @@
Our ill-behaved code should be invoked during GC:
->>> import sys, StringIO
->>> old, sys.stderr = sys.stderr, StringIO.StringIO()
+>>> import sys, io
+>>> old, sys.stderr = sys.stderr, io.StringIO()
>>> g = f()
>>> next(g)
>>> del g
@@ -1796,10 +1796,10 @@
printing warnings and to doublecheck that we actually tested what we wanted
to test.
->>> import sys, StringIO
+>>> import sys, io
>>> old = sys.stderr
>>> try:
-... sys.stderr = StringIO.StringIO()
+... sys.stderr = io.StringIO()
... class Leaker:
... def __del__(self):
... raise RuntimeError