Drop SDK version configuration for Tk compilation, to not bind it to W2k
anymore. Binding it to XP would conflict with Tk's own binding of tkMenu to W2k.
environment variable, to provide an opt-in way to protect against denial of
service attacks due to hash collisions within the dict and set types. Patch
by David Malcolm, based on work by Victor Stinner.
in order to make algorithmic complexity attacks on (e.g.) web apps much more complicated.
The environment variable PYTHONHASHSEED and the new command line flag -R control this
behavior.