(mspools-mode-map): Remove bindings made redundant by `special-mode-map`. (mspools-show): Autoload. Use `erase-buffer`. (mspools-visit-spool): Use `inhibit-read-only`; simplify a bit. (mspools-get-spool-files): Avoid `setq`. Use `pcase-dolist`. (mspools-revert-buffer): Make (unused) args optional. (mspools-help, mspools-show-again, mspools-quit): Declare obsolete.