Small fixes re toggle-read-only, mainly doc

Small fixes re toggle-read-only, mainly doc

* progmodes/hideif.el (hide-ifdef-mode-submap): Also substitute read-only-mode.

* bindings.el (mode-line-toggle-read-only):
* bs.el (bs-toggle-readonly):
* buff-menu.el (Buffer-menu-toggle-read-only):
* dired.el (dired-toggle-read-only):
* files.el (view-read-only, find-file-read-only)
(find-file-read-only-other-window)
(find-file-read-only-other-frame):
* progmodes/hideif.el (hide-ifdef-toggle-outside-read-only):
Doc fixes re toggle-read-only.

* view.el: Comment updates.