Fixes #433 - ORGANIZER e-mail address are case-insensitive

Fixes issue where a recurring meeting is created with ORGANIZER as First.Last@domain.com, then individual appointments are saved with ORGANIZER as first.last@domain.com.

lib/ITip/Broker.php

@@ -847,7 +847,7 @@ protected function parseEventInfo(VCalendar $calendar = null)
                     $organizer = $vevent->ORGANIZER->getNormalizedValue();
                     $organizerName = isset($vevent->ORGANIZER['CN']) ? $vevent->ORGANIZER['CN'] : null;
                 } else {
-                    if ($organizer !== $vevent->ORGANIZER->getNormalizedValue()) {
+                    if (strtoupper($organizer) !== strtoupper($vevent->ORGANIZER->getNormalizedValue())) {
                         throw new SameOrganizerForAllComponentsException('Every instance of the event must have the same organizer.');
                     }
                 }