[Calendar] working listeners

[Calendar] working listeners

[Verification]
eventInit = {description:"HTML5 Introduction",
  summary:"HTML5 Webinar",
  startDate: new tizen.TZDate(2011, 3, 30, 10, 0),
  duration: new tizen.TimeDuration(1, "HOURS"),
  location:"Huesca"};
watcher = {
  onitemsadded: function (items) {
      console.log('entered');
  },
  onitemsupdated: function (items) {
  },
  onitemsremoved: function (ids) {
  }
};
calendar = tizen.calendar.getDefaultCalendar("EVENT");
watcherId = calendar.addChangeListener(watcher);
ev = new tizen.CalendarEvent(eventInit);
calendar.add(ev);

Change-Id: I4e4304fca036d97eccd62676bfebfbebd5f5f3b5
Signed-off-by: Wojciech Kosowicz <w.kosowicz@samsung.com>