Add os.path.supports_unicode_filenames for all platforms,
sys.getwindowsversion() on Windows (new enahanced Tim-proof <wink>
version), and fix test_pep277.py in a few minor ways.
Including doc and NEWS entries.
diff --git a/Doc/lib/libposixpath.tex b/Doc/lib/libposixpath.tex
index 7ad19e3..c5f992b 100644
--- a/Doc/lib/libposixpath.tex
+++ b/Doc/lib/libposixpath.tex
@@ -219,6 +219,13 @@
\var{names} must be modified in place, using \keyword{del} or slice
assignment.)
+\begin{datadesc}{supports_unicode_filenames}
+True if arbitrary Unicode strings can be used as file names (within
+limitations imposed by the file system), and if os.listdir returns
+Unicode strings for a Unicode argument.
+\versionadded{2.3}
+\end{datadesc}
+
\begin{notice}
Symbolic links to directories are not treated as subdirectories, and
that \function{walk()} therefore will not visit them. To visit linked