Provide support for filter registrations

The AbstractDispatcherServletInitializer now provides support for
the registration of filters to be mapped to the DispatcherServlet.
It also sets the asyncSupported flag by default on the
DispatcherServlet and all registered filters.

Issue: SPR-9696

src/reference/docbook/new-in-3.2.xml

@@ -66,7 +66,7 @@
     </section>
 
     <section id="new-in-3.2-webmvc-controller-advice">
-      <title>New <interfacename>@ControllerAdvice</interfacename> annotation</title>
+      <title><interfacename>@ControllerAdvice</interfacename> annotation</title>
       
       <para>Classes annotated with <interfacename>@ControllerAdvice</interfacename>
       can contain <interfacename>@ExceptionHandler</interfacename>,
@@ -88,8 +88,21 @@
       For more details see <xref linkend="mvc-ann-matrix-variables"/>.</para>
     </section>
 
+    <section id="new-in-3.2-dispatcher-servlet-initializer">
+      <title>Abstract base class for code-based Servlet 3+ container initialization</title>
+
+      <para>An abstract base class implementation of the
+      <interfacename>WebApplicationInitializer</interfacename> interface is provided to
+      simplify code-based registration of a DispatcherServlet and filters
+      mapped to it. The new class is named
+      <classname>AbstractDispatcherServletInitializer</classname> and its
+      sub-class <classname>AbstractAnnotationConfigDispatcherServletInitializer</classname>
+      can be used with Java-based Spring configuration.
+      For more details see <xref linkend="mvc-container-config"/>.</para>
+    </section>
+
     <section id="new-in-3.2-webmvc-exception-handler-support">
-      <title>New <classname>ResponseEntityExceptionHandler</classname> class</title>
+      <title><classname>ResponseEntityExceptionHandler</classname> class</title>
 
       <para>A convenient base class with an
       <interfacename>@ExceptionHandler</interfacename>