bug#1806: dired-pop-to-buffer in wrong place

[Stefan Monnier]

>> Please don't use a new variable, but just extend
>> special-display-buffer-names.  It currently already accepts some special
>> parameters such as same-frame, so it could also handle new parameters
>> like `split-orientation' with values `side-by-side' or `top-down'.

> `special-display-popup-frame' is a misnomer (and sits in the wrong file)
> if we continue to overload it with such window specific enhancements.

Hmm... I did write special-display-buffer-names rather than
special-display-popup-frame, didn't I?


        Stefan