Inconsistency in whole buffer buttons.

[Luc Teirlinck]

A while ago, I made the whole buffer "Erase Customization" button ask
for confirmation.  Now all whole buffer buttons (and functions) ask
for confirmation.  For multi-option buffers, that is an improvement.

But there is a difference in single option buffers.  The way I
implemented "Erase Customization", it does _not_ ask for confirmation
in single option buffers.  The others do.  The behavior should be made
uniform in single option buffers one way or the other.  I could easily
make the behavior uniform in either way.

Maybe the way in which we choose to make the behavior uniform depends
on the future direction we want to take for Custom (after the
release).  If we want to go in the direction explained below, it might
be better _not_ to bother the user with confirmation questions in single
option buffers.

Below is my opinion on Custom after the release:

In practice, people already right now use the whole buttons nearly
exclusively in single option buffers, where they are not confusing or
dangerous and do not need confirmation any more than the State Menu
items do.  In single option buffers, the State Menu button is
redundant and all State Menu items that currently have no whole buffer
buttons could be given whole buffer buttons, maybe under the heading
"Advanced".  Then the State button could be deleted from single option
buffers.

In group (or other multi-option) buffers, it may be difficult for
beginners to figure out exactly what the whole buffer buttons and
functions operate on.  The answer is that do _not_ operate on hidden
options nor on options that have been changed outside Custom or are
otherwise "rogue".  (There are very good reasons for that.)  Even for
advanced users who know exactly what they operate on, they are
essentially useless, because if you operate on an entire large Custom
buffer, it just is _way_ to easy to overlook something, confirmation
or no confirmation.

So my idea for after the release would be:

Single option buffers: all current State Menu items become whole
buffer buttons (some under a heading "Advanced"), no State button.

Multiple-option buffer: whole buffer buttons and other whole buffer
functionality only available upon setting a defcustomed option,
disabled by default.  _Maybe_ a State Menu button as now, _maybe_ a
"Customize" button (or link) that if you click on it sets up a single
option buffer.  If the latter, users could replace it with the current
State Menu button using another customizable option.

In other words, for beginning users, group and other multi-option
buffers could be pure browsing tools, actual customization happens in
single-option buffers, after clicking the appropriate "Customize"
button.  I have even heard several advanced users say that they only
customize in single option buffers.  I myself use the State buttons.

Sincerely,

Luc.