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.

setup.py

@@ -460,9 +460,6 @@ class PyBuildExt(build_ext):
         # Fred Drake's interface to the Python parser
         exts.append( Extension('parser', ['parsermodule.c']) )
 
-        # cStringIO
-        exts.append( Extension('cStringIO', ['cStringIO.c']) )
-
         # Memory-mapped files (also works on Win32).
         if platform not in ['atheos', 'mac']:
             exts.append( Extension('mmap', ['mmapmodule.c']) )