Instead of a simple list of disabled plugins, hosts and host groups can
now control whether plugins are enabled or disabled using the
`collectd_plugins` map. The map keys are plugin names, and the values
are booleans indicating if the plugin is enabled.
Using this mechanism, some plugins can be disabled by default (e.g. the
*md* plugin), and enabling them per host or per host group is simpler.
Dustin C. Hatch
29a6a0540f