[DEFAULT] Use SNMP v2c for SNMP checks
[ADDED] Ability to overwrite ipaddress via meta

`node[meta_name]['meta.ipaddress']` can be used to add a monitoring
slave with a different ipaddress than supplied by Chef Ohai.

This is useful, for example, when a node is behind a NAT IP or running
with an Elastic IP in Amazon but still searchable via Chef.
Merge pull request #119 from Bigpoint/meta-ipaddress

Meta ipaddress