Fix SF #659228, 'realpath' function missing from os.path
Also added realpath = abspath for os2emx, similar to windows/mac
which also don't really implement realpath.
Backport candidate, I think?
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 8da9fda..d0179f1 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -17,7 +17,8 @@
"basename","dirname","commonprefix","getsize","getmtime",
"getatime","getctime","islink","exists","isdir","isfile","ismount",
"walk","expanduser","expandvars","normpath","abspath",
- "samefile","sameopenfile","samestat","supports_unicode_filenames"]
+ "samefile","sameopenfile","samestat",
+ "realpath","supports_unicode_filenames"]
# Normalize the case of a pathname. Trivial in Posix, string.lower on Mac.
# On MS-DOS this may also turn slashes into backslashes; however, other