bug#12949: 24.3.50; request: use Customize to set local value (in addition toglobal/default)

[Drew Adams]

> > > This enhancement request is to add an item to the Customize
> > > State menu to set the buffer-local value, for the buffer where
> > > `customize-option' (or whatever) was invoked, to the value as
> > > edited in Customize.
> >
> > Yes, adding the ability of setting buffer-local values would be nice.
> > Being to *save* buffer-local values would also be nice.
> 
> Agreed.

Emacs still needs this, IMO.  Sure wish someone would tackle it.

I guess that a library that wants to make an option _always_
be buffer local can just accompany the defcustom with
(make-variable-buffer-local 'the-option).  But the more
general behavior proposed here would be helpful.