Add a Nagios config helper script

Add a script to help with Nagios installations, which can autogenerate configuration files for the checks, commands, services, hosts, hostgroups, etc needed for these plugins. There is sort of a draft in util/ in the repository.

The script should support dependencies between services to help reduce noise when there is a failure. It should also be able to check the existing configuration for an object to avoid adding duplicates.

The script should read the plugin files and extract "best practice" settings from each one to create recommended services with recommended thresholds, etc. The documentation in each plugin can have some specially formatted meta-data to explain what types of services can be created. For example, the LVM check only does one thing, but the pmp-check-mysql-status can be used for many service checks, such as checking whether the server was restarted recently.

It can also detect the name of the service, and whether it should be run with sudo privileges.