bug#24793: 25.1; Info-quoted face only works if curley quotes are displayed

[Glenn Morris]

Howard Melman wrote:

> The Info-quoted face doesn't seem to do anything in Info
> buffers.
>
> It seems to be because Info-mode-font-lock-keywords assumes
> curley quotes are used.

http://lists.gnu.org/archive/html/emacs-devel/2015-06/msg00000.html
    
    `...' is the quoting used with Texinfo-4, whereas Texinfo uses the
    curly quotes.  The current code recognizes the curly quotes because that
    can be done much more reliably, whereas trying to highlight `...' is
    fraught with too many risks of either false positives or false
    negatives.
    
    While Texinfo 5's performance sucks rocks, the curly quotes output is
    The Right Way, in my opinion, so I don't think it's terribly important
    to highlight the old-style quotes: if you like this highlighting, then
    use Texinfo-5.