Created by: michaelcox
Allows you to set a minLength of 0 for typeahead, in order to show all items in the list. For example, this allows you to show all items up front by binding to the focus of the control. This seems simpler and more flexible than a new option such as showAll or focusShow as suggested in other tickets.
Specifically, this also enables the technique @fat suggested in #3941:
$input.on('focus', $input.typeahead.bind($input, 'lookup')));