#33 Reccurence-id property in version 2.22.1

[GabrielleG]

First of all, thanks a lot for this library.
I noticed a different behavior in case of events having a value in reccurence-id property between version 2.18 and 2.22.1.
When parsing and extracting events in file "agenda_test_recur_event_recurid.ics" (join), with version 2.18, events with reccurence-id appears in period in place of occurences of reccuring events, but in version 2.22.1, it's always occurence of reccuring event which appears.