StateContext may use wrong statemachine

- Tweaking to keep correct statemachine ref around
  so that StateContext passed to actions can be
  used to send events within submachines.
- This was missed due to missing test and i.e. cdplayer
  should transition into playing state directly via
  and event sent from action which when closed is
  checking if cd is inserted.
- Fixes #33

spring-statemachine-samples/cdplayer/src/main/java/demo/cdplayer/Application.java

@@ -196,8 +196,8 @@ public class Application  {
 		@Override
 		public void execute(StateContext<States, Events> context) {
 			if (context.getTransition() != null
-					&& context.getTransition().getSource().getId() == States.CLOSED
-					&& context.getMessageHeader(Variables.CD) != null) {
+					&& context.getTransition().getTarget().getId() == States.CLOSED
+					&& context.getExtendedState().getVariables().get(Variables.CD) != null) {
 				context.getStateMachine().sendEvent(Events.PLAY);
 			}
 		}

spring-statemachine-samples/cdplayer/src/test/java/demo/cdplayer/CdPlayerTests.java

@@ -77,6 +77,18 @@ public class CdPlayerTests {
 		assertLcdStatusContains("cd1");
 	}
 
+	@Test
+	public void testPlayWithCdLoadedDeckOpen() throws Exception {
+		listener.reset(3, 0, 0);
+		player.eject();
+		player.load(library.getCollection().get(0));
+		player.play();
+		listener.stateChangedLatch.await(5, TimeUnit.SECONDS);
+		assertThat(listener.stateChangedCount, is(4));
+		assertThat(machine.getState().getIds(), contains(States.BUSY, States.PLAYING));
+		assertLcdStatusContains("cd1");
+	}
+
 	@Test
 	public void testPlayWithNoCdLoaded() throws Exception {
 		listener.reset(0, 0, 0);