Fix adding reminders
Fix CalendarAlerts

If reminderTime is 15, the time is 20:00 and I have an event at 21:00, the
alert shows up immediatly. Maybe because ALARM_TIME is for "The alarm time of the event, in UTC." not the time in
minutes before beginTime.

It works with CalendarContract.CalendarAlerts.MINUTES.
Specify that reminder interval is in minutes
Merge pull request #6 from brunoqc/fixCalendar

Fix reminders