GitLab

`after-completion' value to request confirm only after TAB.
(confirm-nonexistent-file-or-buffer): New function.
(read-buffer-to-switch, find-file, find-file-other-window)
(find-file-other-frame, find-file-read-only)
(find-file-read-only-other-window)
(find-file-read-only-other-frame): Use it.
(switch-to-buffer-other-window, switch-to-buffer-other-frame): Doc
fix.