uORB::Publication simplify and cleanup

- base class is now template
 - drop linked list
 - virtualization no longer required

src/examples/segway/BlockSegwayController.cpp

@@ -61,6 +61,6 @@ void BlockSegwayController::update()
 		actuators.control[CH_RIGHT] = -_manual.get().x;
 	}
 
-	// update all publications
-	updatePublications();
+	// publish
+	_actuators.update();
 }

src/examples/segway/blocks.cpp

@@ -95,7 +95,7 @@ BlockUorbEnabledAutopilot::BlockUorbEnabledAutopilot(SuperBlock *parent, const c
 	_status(ORB_ID(vehicle_status), 20, 0, &getSubscriptions()),
 
 	// publications
-	_actuators(ORB_ID(actuator_controls_0), -1, &getPublications())
+	_actuators(ORB_ID(actuator_controls_0))
 {
 }
 

src/examples/segway/blocks.hpp

@@ -102,7 +102,8 @@ protected:
 	uORB::SubscriptionPollable<vehicle_status_s> _status;
 
 	// publications
-	uORB::Publication<actuator_controls_s> _actuators;
+	uORB::PublicationData<actuator_controls_s> _actuators{ORB_ID(actuator_controls_0)};
+
 public:
 	BlockUorbEnabledAutopilot(SuperBlock *parent, const char *name);
 	virtual ~BlockUorbEnabledAutopilot() = default;