Introduce Component::setComponents method

[julienbourdeau]

I'm adding this method because I usually have an array of Events and I just want to pass them all to the calendar, without iterating over the list. It doesn't look like much but I think it keeps my code clearer.

In this method, we lose type safety, but I assume people know what they're doing.

// before
foreach ($events as $event) {
    $calendar->addComponent($event);
}

// after
$calendar->setComponents($events);

[markuspoerschke]

Thanks for your contribution! This change will be available in 0.15.0!