BoV: Updated Java version compatibility notes to Java 8.

Change-Id: I8facb7e89af09eec3331c21e04124b5e5827a66e

documentation/advanced/advanced-logging.asciidoc

 public class MyClass {
   private final static Logger logger =
           Logger.getLogger(MyClass.class.getName());
-  
+
   public void myMethod() {
     try {
       // do something that might fail
     } catch (Exception e) {
       logger.log(Level.SEVERE, "FAILED CATASTROPHICALLY!", e);
-    } 
+    }
   }
 }
 ----
+ifdef::vaadin7[]
 
 ((("static")))
 ((("memory
 hence leaking memory. As the size of the PermGen memory where class object are
 stored is fixed, the leakage will lead to a server crash after many
 redeployments. The issue depends on the way how the server manages classloaders,
-on the hardness of the back-references, and may also be different between Java 6
-and 7. So, if you experience PermGen issues, or want to play it on the safe
-side, you should consider using non-static [classname]#Logger# instances.//As
-discussed in Forum thread 1175841
-(24.2.2012).
+on the hardness of the back-references.
+So, if you experience PermGen issues, or want to play it on the safe
+side, you should consider using non-static [classname]#Logger# instances.
+//As discussed in Forum thread 1175841 (24.2.2012).
+endif::vaadin7[]
 
 
 (((range="endofrange", startref="term.advanced.logging")))
-
-

documentation/application/application-events.asciidoc

 [[application.events.anonymous]]
 == Using Anonymous Classes
 
-By far the easiest and the most common way to handle events in Java 6 and 7 is
-to use anonymous local classes. It encapsulates the handling of events to where
+By far the easiest and the most common way to handle events in Java 8 lambdas.
+It encapsulates the handling of events to where
 the component is defined and does not require cumbering the managing class with
 interface implementations. The following example defines an anonymous class that
 inherits the [classname]#Button.ClickListener# interface.
 ----
 // Have a component that fires click events
 final Button button = new Button("Click Me!");
-        
+
 // Handle the events with an anonymous class
 button.addClickListener(new Button.ClickListener() {
     public void buttonClick(ClickEvent event) {
 ----
 public class Java8Buttons extends CustomComponent {
     public Java8Buttons() {
-        setCompositionRoot(new HorizontalLayout( 
+        setCompositionRoot(new HorizontalLayout(
             new Button("OK", this::ok),
             new Button("Cancel", this::cancel)));
     }
-    
+
     public void ok(ClickEvent event) {
         event.getButton().setCaption ("OK!");
     }
 
     public MyComposite() {
         Layout layout = new HorizontalLayout();
-        
+
         // Just a single component in this composition
         button = new Button("Do not push this");
         button.addClickListener(this);
         layout.addComponent(button);
-        
+
         setCompositionRoot(layout);
     }
-    
+
     // The listener method implementation
     public void buttonClick(ClickEvent event) {
         button.setCaption("Do not push this again");
         toobutton = new Button("A Button Too", this);
 
         // Put them in some layout
-        Layout root = new HorizontalLayout(); 
+        Layout root = new HorizontalLayout();
         root.addComponent(onebutton);
         root.addComponent(toobutton);
         setCompositionRoot(root);
     }
-    
+
     @Override
     public void buttonClick(ClickEvent event) {
         // Differentiate targets by event source
 or any other visible text is generally discouraged, as it may create problems
 for internationalization. Using other symbolic strings can also be dangerous,
 because the syntax of such strings is checked only at runtime.
-
-
-
-

documentation/getting-started/getting-started-idea.asciidoc

 
 . Enter a [guilabel]#Project name# and [guilabel]#Project location#, and select
 the [guilabel]#Java SDK# to be used for the project.
-Vaadin requires at least Java 6.
+Vaadin requires at least Java 8.
 If you have not configured a Java SDK previously, you can configure it here.
 +
 image::img/idea-newproject-1.png[scaledwidth=100%]
 //<?dbfo-need height="8cm" ?>
 
 . Enter a project name, location, and the Java SDK to be used for the project.
-Vaadin requires at least Java 6.
+Vaadin requires at least Java 8.
 +
 image::img/idea-maven-newproject-1.png[scaledwidth=100%]
 +

documentation/installing/installing-toolchain.adoc

 In this example, we use the following toolchain:
 
 * Windows, Linux, or Mac OS X
-* link:http://www.oracle.com/technetwork/java/javase/downloads/index.html[Oracle Java SE 8] (Java 6 or newer is required)
+* link:http://www.oracle.com/technetwork/java/javase/downloads/index.html[Oracle Java SE 8]
 * link:http://www.eclipse.org/downloads/[Eclipse IDE for Java EE Developers]
 * link:http://tomcat.apache.org/[Apache Tomcat 8.0 (Core)]
 * link:http://www.getfirefox.com/[Mozilla Firefox] browser