Multiple animations closing at the same time breaks positioning

[aleho]

If multiple notifications close at the same time (e.g. via a timer), positioning of all notifications is horribly broken (spaces, big offset).

This apparently doesn't happen with "newest_on_top" set to true.

Test case to reproduce:

(function ($) {
    function showNotification(delay) {
        this._counter = (this._counter || 0) + 1;

        $.notify({
            message: 'Notification ' + this._counter,
        }, {
            showProgressbar: !!delay,
            newest_on_top: false,
            delay: delay || false,
            timer: 50,
            animate: {
                enter: 'animated fadeInDown',
                exit: 'animated fadeOutUp'
            }
        });
    }

    showNotification(10);
    showNotification(10);
    showNotification();
    showNotification(10);
    showNotification();
    showNotification(10);
    showNotification(10);
})(jQuery);