bug#37390: 26.3; ediff-buffers appears to have a focus issue

[martin rudalics]

> For YEARS I've been using a separate frame for control. I'll just toggle
> that off. No issues with that in 26.2. I will try in 26.3. And now that I
> see it, why the heck would you want a separate frame? To have multiple
> diffs going at the same time?

'ediff-window-setup-function' has a misguided default value.  Luckily
you can change it - the speedbar, for example, doesn't allow to do
that.  I'm using 'ediff-setup-windows-plain' ever since together with
'ediff-split-window-function' set to 'split-window-horizontally'.

martin