Menu may still render when autocomplete is disabled

When the autocomplete plugin is disabled with outstanding ajax requests, the menu will still render when the request returns.

Proposed fix:

Add !this.options.disabled to if statement in _response.

E.g.,

_response: function( content ) {
    if ( !this.options.disabled && content && content.length ) {
        content = this._normalize( content ); 
        this._suggest( content ); 
        this._trigger( "open" );
    } else {
        this.close();
    } this.element.removeClass( "ui-autocomplete-loading" );
}

This flaw becomes very apparent when constructing completely ajax-driven pages where the autocomplete plugin may need to be forsibly closed every time e.g., a button is pressed.

Autocomplete: Abort pending ajax requests when disabled and prevent handling results when disabled. Fixes #6752 - Menu may still render when autocomplete is disabled.

Changeset: 0d0c86210c4a6473888089ddcea918df8c156022

Autocomplete: Abort pending ajax requests when disabled and prevent handling results when disabled. Fixes #6752 - Menu may still render when autocomplete is disabled.

Changeset: d2a12ff825ebb0e620b25abdbcbaf024881ef537