ntp security and bug fix update

[4.2.6p5-10]

• don’t accept server/peer packets with zero origin timestamp (CVE-2015-8138)
• fix crash with reslist command (CVE-2015-7977, CVE-2015-7978)
  [4.2.6p5-9]
• fix crash with invalid logconfig command (CVE-2015-5194)
• fix crash when referencing disabled statistic type (CVE-2015-5195)
• don’t hang in sntp with crafted reply (CVE-2015-5219)
• don’t crash with crafted autokey packet (CVE-2015-7691, CVE-2015-7692,
  CVE-2015-7702)
• fix memory leak with autokey (CVE-2015-7701)
• don’t allow setting driftfile and pidfile remotely (CVE-2015-7703)
• don’t crash in ntpq with crafted packet (CVE-2015-7852)
• add option to set Differentiated Services Code Point (DSCP) (#1228314)
• extend rawstats log (#1242895)
• fix resetting of leap status (#1243034)
• report clock state changes related to leap seconds (#1242937)
• allow -4/-6 on restrict lines with mask (#1232146)
• retry joining multicast groups (#1288534)
• explain synchronised state in ntpstat man page (#1286969)
  [4.2.6p5-7]
• check origin timestamp before accepting KoD RATE packet (CVE-2015-7704)
• allow only one step larger than panic threshold with -g (CVE-2015-5300)