CAP-145 ETag follows spec
CAP-144 Display server error messages to user
NOJIRA: fix CalendarHelper.getEventList : retrieve events of ALL calendars (and not just of only one)
Merge pull request #14 from vbonamy/EventsOfALLCalendarsFix

CAP-147:  New CalendarHelper class ignores/discards events from all but one calendar definition
Merge pull request #13 from jameswennmacher/CAP-145

CAP-145 ETag follows spec
Merge pull request #12 from jameswennmacher/CAP-144

CAP-144 Display server error messages to user