Autocomplete: ui-autocomplete-loading class not removed when Ajax request times out

[doerwalter]

When the autocomplete source function does an Ajax request with a timeout value, and the request exceeds the timeout limit, the ui-autocomplete-loading CSS class will never get removed from the input control.

[Scott González]

Autocomplete: Handle ajax errors and timeouts. Fixes #6692 - Autocomplete: ui-autocomplete-loading class not removed when Ajax request times out.

Changeset: 40135bb09130a56aabc0d185b62a597cb45df0dc

[doerwalter]

Changeset 40135bb09130a56aabc0d185b62a597cb45df0dc fixes the problem for the simple case, i.e. when the source option is the ajax URL. However when the source options is not a string, but a function, the problem isn't fixed. I realize that it might be unfixable without any changes to the API, but at least there should be a way to cancel the autocomplete (e.g. by calling response(null)) and it should be documented that response *must* be called even in case of an error/timeout.

[scottgonzalez]

I've updated the docs.