[Alarm]: Implementation of Tizen alarm API.

This commit implements the Alarm API:
  https://developer.tizen.org/dev-guide/2.2.0/org.tizen.web.device.apireference/tizen/alarm.html

There is a known issue about repeat alarm: if the working system time zone is set to Daylight saving time like PDT or EDT, the repeat alarm finds 3600 seconds gap on the initial trigger time.
please add one blank line