Continue to fix bug#25607

Continue to fix bug#25607

* lisp/ido.el (ido-complete): Let-bind `non-essential' to nil.
(ido-file-name-all-completions-1): Do not bind `non-essential'.

* lisp/net/tramp.el: (tramp-completion-file-name-handler):
Improve autoloaded version.
(tramp-completion-file-name-handler): Remove old compat code.
Check only for `tramp-completion-mode-p'.
(tramp-completion-mode-p): Autoload.  Do not check any longer
for `last-input-event'.
(tramp-completion-handle-expand-file-name): Simplify.  (Bug#25607)