!act,doc #3831 Adding more Java with Lambda documentation and support

* The Java with Lambda support documentation for AbstractActor and AbstractFSM are now on par with Scala
* Many small fixes and additions of missing things
* Added an AbstractActorContext that has convenience functions for getChild and getChildren

akka-samples/akka-docs-java-lambda/src/test/java/docs/actor/InitializationDocTest.java

@@ -0,0 +1,67 @@
+/**
+ * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
+ */
+
+package docs.actor;
+
+import akka.actor.*;
+import akka.japi.pf.ReceiveBuilder;
+import akka.testkit.JavaTestKit;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import scala.PartialFunction;
+import scala.concurrent.duration.Duration;
+import scala.runtime.BoxedUnit;
+
+import java.util.concurrent.TimeUnit;
+
+public class InitializationDocTest {
+
+  static ActorSystem system = null;
+
+  @BeforeClass
+  public static void beforeClass() {
+    system = ActorSystem.create("InitializationDocTest");
+  }
+
+  @AfterClass
+  public static void afterClass() {
+    system.shutdown();
+    system.awaitTermination(Duration.create("5 seconds"));
+  }
+
+  public static class MessageInitExample extends AbstractActor {
+    //#messageInit
+    private String initializeMe = null;
+
+    @Override
+    public PartialFunction<Object, BoxedUnit> receive() {
+      return ReceiveBuilder.
+        matchEquals("init", m1 -> {
+          initializeMe = "Up and running";
+          context().become(ReceiveBuilder.
+            matchEquals("U OK?", m2 -> {
+              sender().tell(initializeMe, self());
+            }).build());
+        }).build();
+    }
+    //#messageInit
+  }
+
+  @Test
+  public void testIt() {
+
+    new JavaTestKit(system) {{
+      ActorRef testactor = system.actorOf(Props.create(MessageInitExample.class), "testactor");
+      String msg = "U OK?";
+
+      testactor.tell(msg, getRef());
+      expectNoMsg(Duration.create(1, TimeUnit.SECONDS));
+
+      testactor.tell("init", getRef());
+      testactor.tell(msg, getRef());
+      expectMsgEquals("Up and running");
+    }};
+  }
+}