bug#10186: 23.3; save-some-buffers not making review windows large enough

[Juri Linkov]

>> I think there should a rule for display-buffer to skip small windows.
>
> Apologies for not following this thread.  But what would be the definition of 
> a
> "small window"?  And what if the buffer content itself is "small"?

In `make-small-windows-softly-dedicated', Martin used the constant 10
to define the minimal size of a "small window".

Incidentally, this is the same number as the default value of
`window-min-width'.  But the default value of `window-min-height' is 4
that is smaller for a reasonable size of a "small window".

So maybe as there are already `window-safe-min-height' and
`window-safe-min-width', we could add new options like
`window-comfortable-min-height' and `window-comfortable-min-width'.