bug#12166: 24.1.50; display-buffer documentation should mention display-buffer-function

[Chong Yidong]

martin rudalics <rudalics@gmx.at> writes:

>> The documentation of display-buffer in the elisp guide does not mention
>> display-buffer-function.  It should probably mention that if
>> display-buffer-function is non-nil, display-buffer will use that
>> function in order to display the buffer, and will not fall back to any
>> of the various possible display actions.
>
> `display-buffer-function' will be declared obsolete in the near future.
> I suppose that's the reason why it is no more mentioned in the Elisp
> manual (you can read about it in the Elisp manual for Emacs 23).

I just marked it obsolete.