Documentation improvements

* Re enabling Java tests in akka-docs (they were not run before)
* Fixed bug #19764
* #19735 Rewrote every sample using the deprecated PushPullStage and friends
  using GraphStage
* Pruned old unused graph images
* Added missing graffle file for new graph images

akka-docs/rst/java/code/docs/actorlambda/ActorDocTest.java

@@ -11,6 +11,7 @@ import akka.testkit.EventFilter;
 import akka.testkit.TestEvent;
 import com.typesafe.config.Config;
 import com.typesafe.config.ConfigFactory;
+import docs.AbstractJavaTest;
 import scala.PartialFunction;
 import scala.runtime.BoxedUnit;
 import static docs.actorlambda.Messages.Swap.Swap;
@@ -45,7 +46,7 @@ import scala.concurrent.Future;
 import static akka.pattern.Patterns.gracefulStop;
 //#import-graceFulStop
 
-public class ActorDocTest {
+public class ActorDocTest extends AbstractJavaTest {
 
   public static Config config = ConfigFactory.parseString(
     "akka {\n" +

akka-docs/rst/java/code/docs/actorlambda/FaultHandlingTest.java

@@ -14,6 +14,7 @@ import akka.japi.pf.DeciderBuilder;
 import akka.japi.pf.ReceiveBuilder;
 import com.typesafe.config.Config;
 import com.typesafe.config.ConfigFactory;
+import docs.AbstractJavaTest;
 import scala.PartialFunction;
 import scala.concurrent.Await;
 import static akka.pattern.Patterns.ask;
@@ -35,7 +36,7 @@ import org.junit.AfterClass;
 import scala.runtime.BoxedUnit;
 
 //#testkit
-public class FaultHandlingTest {
+public class FaultHandlingTest extends AbstractJavaTest {
 //#testkit
 
   public static Config config = ConfigFactory.parseString(

akka-docs/rst/java/code/docs/actorlambda/InitializationDocTest.java

@@ -10,6 +10,7 @@ import akka.actor.Props;
 import akka.japi.pf.FI;
 import akka.japi.pf.ReceiveBuilder;
 import akka.testkit.JavaTestKit;
+import docs.AbstractJavaTest;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -18,7 +19,7 @@ import scala.concurrent.duration.Duration;
 
 import java.util.concurrent.TimeUnit;
 
-public class InitializationDocTest {
+public class InitializationDocTest extends AbstractJavaTest {
 
   static ActorSystem system = null;
 

akka-docs/rst/java/code/docs/actorlambda/SampleActorTest.java

@@ -8,13 +8,14 @@ import akka.actor.ActorRef;
 import akka.actor.ActorSystem;
 import akka.actor.Props;
 import akka.testkit.JavaTestKit;
+import docs.AbstractJavaTest;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
 import static org.junit.Assert.*;
 
-public class SampleActorTest {
+public class SampleActorTest extends AbstractJavaTest {
 
   static ActorSystem system;
 

akka-docs/rst/java/code/docs/actorlambda/fsm/BuncherTest.java

@@ -8,6 +8,7 @@ import akka.actor.ActorRef;
 import akka.actor.ActorSystem;
 import akka.actor.Props;
 import akka.testkit.JavaTestKit;
+import docs.AbstractJavaTest;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -20,7 +21,7 @@ import static docs.actorlambda.fsm.Events.SetTarget;
 import static docs.actorlambda.fsm.Events.Flush.Flush;
 
 //#test-code
-public class BuncherTest {
+public class BuncherTest extends AbstractJavaTest {
 
   static ActorSystem system;
 

akka-docs/rst/java/code/docs/actorlambda/fsm/FSMDocTest.java

@@ -6,6 +6,7 @@ package docs.actorlambda.fsm;
 
 import akka.actor.*;
 import akka.testkit.JavaTestKit;
+import docs.AbstractJavaTest;
 import org.hamcrest.CoreMatchers;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -18,7 +19,7 @@ import static docs.actorlambda.fsm.FSMDocTest.StateType.*;
 import static docs.actorlambda.fsm.FSMDocTest.Messages.*;
 import static java.util.concurrent.TimeUnit.*;
 
-public class FSMDocTest {
+public class FSMDocTest extends AbstractJavaTest {
   static ActorSystem system;
 
   @BeforeClass