(by returning the original object unchanged).

This removes the need to add externals/tcltk[64]/bin to PATH to be able
to import tkinter.  Also documents the necessity for the DLLs to be
on PATH or in python.exe's directory.

Moves Windows installer externals onto SVN and updates the build process to grab them automatically.

Patch written by Bernt Røskar Brenna.

self.__class__ in __repr__() and __reduce__() for simplicity and reliability.

Patch by Christie.

Reported by Antony Lee.

Explain why calling os.open() with os.O_TMPFILE is a safe test to check if
O_TMPFILE is supported by the running kernel.

calculation fails.

This one should make Docs 3.5 and Docs 3.x green again.

This should make buildbots green.

This should make buildbots green.

Patch by Louis Sautier.