Use of "?" for help has been deprecated for 8 years, can we drop it?

[Markus Armbruster <armbru@redhat.com>]

We deprecated "?" more than eight years ago.  We didn't have a
deprecation process back then, but we did purge "?" from the
documentation and from help texts.  Can we finally drop it?

I'm asking because there is a patch on the list that bypasses
is_help_option() to not add deprecated "?" to a new place: "[PATCH v2
1/4] keyval: Parse help options".



commit c8057f951d64de93bfd01569c0a725baa9f94372
Author: Peter Maydell <peter.maydell@linaro.org>
Date:   Thu Aug 2 13:45:54 2012 +0100

    Support 'help' as a synonym for '?' in command line options
    
    For command line options which permit '?' meaning 'please list the
    permitted values', add support for 'help' as a synonym, by abstracting
    the check out into a helper function.
    
    This change means that in some cases where we were being lazy in
    our string parsing, "?junk" will now be rejected as an invalid option
    rather than being (undocumentedly) treated the same way as "?".
    
    Update the documentation to use 'help' rather than '?', since '?'
    is a shell metacharacter and thus prone to fail confusingly if there
    is a single character filename in the current working directory and
    the '?' has not been escaped. It's therefore better to steer users
    towards 'help', though '?' is retained for backwards compatibility.
    
    We do not, however, update the output of the system emulator's -help
    (or any documentation autogenerated from the qemu-options.hx which
    is the source of the -help text) because libvirt parses our -help
    output and will break. At a later date when QEMU provides a better
    interface so libvirt can avoid having to do this, we can update the
    -help text too.
    
    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

commit 585f60368f23e6603cf86cfdaeceb89d1169f4b8
Author: Peter Maydell <peter.maydell@linaro.org>
Date:   Thu Oct 4 16:22:01 2012 +0100

    qemu-options.hx: Change from recommending '?' to 'help'
    
    Update the -help output and documentation so that it recommends
    'help' rather than '?' for the various "list valid values for this
    option" cases. '?' is deprecated (as it can fail confusingly if
    not quoted), so it's better to steer users towards 'help'. ('?'
    still works, for backwards compatibility.)
    
    This is the -help option part of the change otherwise done in
    commit c8057f9, since we are now past release 1.2 and free to
    change our help text without worrying about breaking libvirt.
    
    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
    Reviewed-by: Eric Blake <eblake@redhat.com>
    Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>