lisp/ido.el: Respect completion-auto-help setting
This commit makes ido completion respect the user's setting for `completion-auto-help' by default. It does this by defining a wrapper function `ido-completion-auto-help', which calls `ido-completion-help' only when `completion-auto-help' is non-nil. * lisp/ido.el (ido-completion-auto-help): New function. (ido-cannot-complete-command): Use it as the new default (bug#41340).