[PDI-12259] As an Administrator, I want the ability to monitor metrics using a 3rd party SNMP console (Phase 1, SNMP traps)
	- created kettle-monitoring-plugin as the first step ( read: entry-point ) to PDI monitoring story
	- new plugin's underlying structure is PDI Extension points ( see http://wiki.pentaho.com/display/EAI/PDI+Extension+Point+Plugins )
[PDI-12259] As an Administrator, I want the ability to monitor metrics using a 3rd party SNMP console (Phase 1, SNMP traps)
	- updated, now the async event bus has been implemented and is available in platform
	- MonitoringEnvironment registers on startup all of the plugin's event subscribers (aka event handlers) on the platform's async event bus
	- at each extension point plugin trigger, an Event class is created and posted to the platform's async event bus