Create two new events to signal enabling and disabling of transports

briar-api/src/org/briarproject/api/event/TransportEnabledEvent.java

@@ -0,0 +1,17 @@
+package org.briarproject.api.event;
+
+import org.briarproject.api.TransportId;
+
+/** An event that is broadcast when a transport is enabled. */
+public class TransportEnabledEvent extends Event {
+
+	private final TransportId transportId;
+
+	public TransportEnabledEvent(TransportId transportId) {
+		this.transportId = transportId;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+}