New macro with-temp-buffer-window and related fixes.

* buffer.c (Fdelete_all_overlays): New function.

* window.el (temp-buffer-window-setup-hook)
(temp-buffer-window-show-hook): New hooks.
(temp-buffer-window-setup, temp-buffer-window-show)
(with-temp-buffer-window): New functions.
(fit-window-to-buffer): Remove unused optional argument
OVERRIDE.
(special-display-popup-frame): Make sure the window used shows
BUFFER.

* help.el (temp-buffer-resize-mode): Fix doc-string.
(resize-temp-buffer-window): New optional argument WINDOW.

* files.el (recover-file, save-buffers-kill-emacs):
* dired.el (dired-mark-pop-up): Use with-temp-buffer-window.