bug#19355: 25.0.50; limit the popup window height

[martin rudalics]

> Try emacs 24.4 and compare. I think it is a bug.

You're right.  The behavior changed completely.  Could you try to
replace in `minibuffer-completion-help' the form

(window-height . fit-window-to-buffer)

with

,(when temp-buffer-resize-mode
   '(window-height . resize-temp-buffer-window))

and test whether it restores the old behavior (with
`temp-buffer-resize-mode' en- and disabled)?

Thanks, martin