bug#5742: Customize and obsolete options

[Glenn Morris]

Severity: wishlist

Customize does not seem to indicate in any way when options are
obsolete. Eg

emacs -Q -l diary-lib
C-h v diary-face

  This variable is obsolete since 23.1;
  customize the face `diary' instead.


But if I do

M-x customize-variable diary-face

there is no mention if it being obsolete.

I think it would be good to mention the obsolescence in the Customize
buffer in some way.


When browsing a group, eg with

M-x customize-group calendar-faces

it might be nice if the obsolete options were presented in a subdued
face if they had the default value (to indicate they should not be
customized), and perhaps in a more strident face if they had been
customized (to indicate that the user should check these settings and
perhaps migrate them to the newer way of doing things.)