Fix a bunch of typos in documentation, docstrings and comments.
(From SF patch #810751)
diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index fcb899b..687d885 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -301,7 +301,7 @@
# For each directory under top (including top itself, but excluding
# '.' and '..'), func(arg, dirname, filenames) is called, where
# dirname is the name of the directory and filenames is the list
-# files files (and subdirectories etc.) in the directory.
+# of files (and subdirectories etc.) in the directory.
# The func may modify the filenames list, to implement a filter,
# or to impose a different order of visiting.