bug#20351: isearch-lax-whitespace should be customizable variable

[Eli Zaretskii]

> From: Stefan Monnier <monnier@IRO.UMontreal.CA>
> Date: Sun, 05 Jul 2015 12:06:54 -0400
> Cc: 20351@debbugs.gnu.org, Artur Malabarba <bruce.connor.am@gmail.com>,
>       Ken T Takusagawa <kenta@mit.edu>, Juri Linkov <juri@linkov.net>
> 
> > The technical term is "equivalence classes".
> 
> I don't think so.  This term would apply equally well to case-fold-search.

No, I don't think so.  Case equivalence and canonical/compatibility
equivalence are separate aspects.