bug#20322: 25.0.50; indent-tabs-mode should default to nil

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  20322@debbugs.gnu.org
> Date: Fri, 17 Apr 2015 09:55:40 +0200
> 
> Dmitry Gutov <dgutov@yandex.ru> writes:
> 
> > I'm not aware of any popular programming language that doesn't work with
> > tabs for indentation.
> 
> Python is a prominent example (if you use a non-default tab width).

Indeed, and python.el already sets indent-tabs-mode to nil in its mode
function.