* [EventKit] Obsolete the EKAlarm constructor and update tests.
Apple's documentation says "Use the alarmWithAbsoluteDate: and
alarmWithRelativeOffset: class methods to create an alarm", and additionally
calling the default constructor crashes, so obsolete the constructor and don't
call it from tests either.
* [EventKit] Make EKCalendarItem abstract according to Apple's documentation.
Since EKCalendarItem is an abstract class, tests should obviously not create
instances of it - and in fact it fails:
[FAIL] CalendarItemTest.NullAllowedTest : Foundation.MonoTouchException : Objective-C exception thrown. Name: NSInvalidArgumentException Reason: +[EKCalendarItem frozenClass]: unrecognized selector sent to class 0x10e02bfa0
* [tests] Remove removed file from xammac tests as well.
Timothy Risi
Alex Soto
Rolf Bjarne Kvinge