Security update for ntp (important)

This update for ntp fixes the following issues:

• Separate the creation of ntp.keys and key #1 in it to avoid problems
  when upgrading installations that have the file, but no key #1, which is
  needed e.g. by "rcntp addserver".

• Update to 4.2.8p7 (bsc#977446):

  • CVE-2016-1547, bsc#977459: Validate crypto-NAKs, AKA: CRYPTO-NAK DoS.
  • CVE-2016-1548, bsc#977461: Interleave-pivot
  • CVE-2016-1549, bsc#977451: Sybil vulnerability: ephemeral association
    attack.
  • CVE-2016-1550, bsc#977464: Improve NTP security against buffer
    comparison timing attacks.
  • CVE-2016-1551, bsc#977450: Refclock impersonation vulnerability
  • CVE-2016-2516, bsc#977452: Duplicate IPs on unconfig directives will
    cause an assertion botch in ntpd.
  • CVE-2016-2517, bsc#977455: remote configuration trustedkey/
    requestkey/controlkey values are not properly validated.
  • CVE-2016-2518, bsc#977457: Crafted addpeer with hmode > 7 causes array
    wraparound with MATCH_ASSOC.
  • CVE-2016-2519, bsc#977458: ctl_getitem() return value not always
    checked.
  • integrate ntp-fork.patch
  • Improve the fixes for: CVE-2015-7704, CVE-2015-7705, CVE-2015-7974

• Restrict the parser in the startup script to the first
  occurrance of "keys" and "controlkey" in ntp.conf (bsc#957226).