Update timezone data to 2015f

  Changes affecting future time stamps

    North Korea switches to +0830 on 2015-08-15.  (Thanks to Steffen Thorsen.)
    The abbreviation remains "KST".  (Thanks to Robert Elz.)

    Uruguay no longer observes DST.  (Thanks to Steffen Thorsen
    and Pablo Camargo.)

  Changes affecting past and future time stamps

    Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
    (Thanks to Roman Tudos.)

Bug: 23480367
Change-Id: I6a46b79be3a547d4af5f3f7ca1452640ed764e1c