bug#21959: [25.1.50.1] No way to save customization from emacs -Q

[Eli Zaretskii]

> From: Random832 <random832@fastmail.com>
> Date: Fri, 20 Nov 2015 14:43:32 +0000 (UTC)
> 
> On 2015-11-20, Eli Zaretskii <eliz@gnu.org> wrote:
> > AFAIU, Customize cannot _update_ your settings (which might include
> > customizations of more than one feature) without _loading_ them from
> > your ~/.emacs first.
> 
> Why can't it "load" it (into a "saved but not set" state, or where the default
> value is considered "set and not saved") without _applying_ the settings, by
> simply reading from your .emacs when you first run customize?

Patches welcome.