linux: add OVH nameservers
nagios: fix check_splunk
fix nagios aggregate check
ntp: use global pool servers by default
chef: upgrade server to 11.1.6
hadoop2: increase thresholds for checkpoint check to prevent false positives
nagios: add URL to documentation of service checks
fix vagrant issues
hadoop2: upgrade to 2.5.2
druid: upgrade to 0.6.160
druid: add histogram module
aerospike: add backup
postgreswl: only run backup script on one cluster member
linux: add global agignore
kafka: add log.retention.bytes
lxc: use the hosts gateway as container gateway by default
smart: do not override default check intervals
ignore host key during node bootstrap