[Python-3000] Support for PEP 3131

[Stephen J. Turnbull]

Steve Howell writes:

 > Then, for all the other classes of users (Dutch tax
 > lawyer who still doesn't want Sanskrit, etc.), do you
 > advocate having multiple convenient ways to specify
 > their desired character set (command line flag, env
 > setting, magic directive at top of file, etc.), or do
 > you want the "one true way"?

-1 on magic directive.  That delegates the decision to the file.
That's not what we want here.

+1 on "command line only".  Ie, force the user to redefine the
Python command with an alias or something if they want to set a
different default from site policy.