[python-win32] Properly encoded HTML from MSXML XLST processor into

[Roger Upole]

See this thread for some discussion and examples of creating
an object that implements IStream:
http://mail.python.org/pipermail/python-win32/2007-August/006166.html

Future builds will also have pythoncom.CreateStreamOnHGlobal
for a quick and simple way to create an in-memory IStream.

        Roger