Running the Cyrus test suite

implicitcancels

Not sending a CANCEL when an EXDATE is added. Need to ensure that's the only difference.

put

Reveals that the Cyrus validator is partially incorrect and that bedeworks update of dtstamp is also partially incorrect.

DTSTAMP from rfc5545:

   Purpose:  In the case of an iCalendar object that specifies a
      "METHOD" property, this property specifies the date and time that
      the instance of the iCalendar object was created.  In the case of
      an iCalendar object that doesn't specify a "METHOD" property, this
      property specifies the date and time that the information
      associated with the calendar component was last revised in the
      calendar store.
...
      In the case of an iCalendar object that specifies a "METHOD"
      property, this property differs from the "CREATED" and "LAST-
      MODIFIED" properties.  These two properties are used to specify
      when the particular calendar data in the calendar store was
      created and last modified.  This is different than when the
      iCalendar object representation of the calendar service
      information was created or last modified.

      In the case of an iCalendar object that doesn't specify a "METHOD"
      property, this property is equivalent to the "LAST-MODIFIED"
      property.