wmstartup: Add more services, move service logic out of common.bash

.config/dtfscripts/services/compton.dtf

@@ -10,14 +10,11 @@ source $DTF_SERVICES_DIR/common.bash
 service_name="Compton"
 service_process="compton"
 
-function start() {
+function prestart-extra() {
 	if [[ "$HOST" == "vm-*" ]]; then
 		svc_log "Will not start: in a VM"
-		return 0
-	else
-		svc_log "Starting"
-		$service_process > /dev/null 2>&1 &
-		return 0
+		return 1
 	fi
+	return 0
 }