Add check-netstat-tcp.rb, heavily based on metrics-netstat-tcp.rb
opsgenie heartbeat: use apiKey and (new!) source config
consistently use '...'
check-netstat-tcp.rb fixes since it's a check not a metric
adding gluster/gluster-georepl-status.rb

- plugin to check if Gluster's geo-replication is healthy or not.
added flag to pass states
bugfix: requires sudo
renamed check and made it executable
added more exclusions
fix json syntax in plugin example configs
add ipv6 support to check-netstat-tcp.rb
Change message format handed to Logstash.

Matches https://logstash.jira.com/browse/LOGSTASH-675
check-sftp - Added new file count and aging checks
Type is not mandatory for Logstash's schema v1.
Oops.
check messages in individual queue
Add snmp bulk-walk metric collection plugin
Add some documentation to commandline parameters
Checks for ElasticSearch 0.9x and 1.x

/_cluster/nodes/_local has been retired with ES 1.0, so this check does
not work anymore.
By identifying the cluster version before running the check,
we can adjust the URL.
Add docker/check-docker-containers.rb