Pass unhandled messages up to the cloud

Currently these DTHs return null when they parse a message that they
don't have specific handling for.  This ends up sending the message up
to the cloud as an event, which prevented us from potentially parsing
that message in the cloud.  By instead returning an empty map we can
instead send the message up to the cloud to be parsed there.  This
allows us to add handling in the cloud for new message without requiring
and AppEngine deploy for them to work.

This resolves: https://smartthings.atlassian.net/browse/DPROT-200

devicetypes/smartthings/smartpower-dimming-outlet.src/smartpower-dimming-outlet.groovy

@@ -69,15 +69,17 @@ metadata {
 def parse(String description) {
 	log.debug "description is $description"
 
+	def event = [:]
 	def finalResult = isKnownDescription(description)
 	if (finalResult != "false") {
 		log.info finalResult
 		if (finalResult.type == "update") {
 			log.info "$device updates: ${finalResult.value}"
+			event = null
 		}
 		else if (finalResult.type == "power") {
 			def powerValue = (finalResult.value as Integer)/10
-			sendEvent(name: "power", value: powerValue)
+			event = createEvent(name: "power", value: powerValue)
 
 			/*
 				Dividing by 10 as the Divisor is 10000 and unit is kW for the device. AttrId: 0302 and 0300. Simplifying to 10
@@ -87,13 +89,14 @@ def parse(String description) {
 			*/
 		}
 		else {
-			sendEvent(name: finalResult.type, value: finalResult.value)
+			event = createEvent(name: finalResult.type, value: finalResult.value)
 		}
 	}
 	else {
 		log.warn "DID NOT PARSE MESSAGE for description : $description"
 		log.debug parseDescriptionAsMap(description)
 	}
+	return event
 }
 
 // Commands to device