(view-read-only): Don't declare a second time.

(view-read-only): Don't declare a second time.
(find-file-read-only, find-file-read-only-other-window)
(find-file-read-only-other-frame): Check that file does exist.
(large-file-warning-threshold): New custom.
(find-file-noselect): Use it.
(report-errors): New macro.
(normal-mode): Use it.
(toggle-read-only): Really toggle, even if view-mode is on.
(parse-colon-path): Remove unused `cd-prefix' var.
(make-backup-file-name-1): Remove unused `failed' var.
(basic-save-buffer): Remove unused `tempsetmodes' var.
(basic-save-buffer-2): Remove unused `temp' var.
(insert-directory): Remove unused `available' var.