Add Jackson 2 HttpMessageConverter and View

Jackson 2 uses completely new package names and new maven artifact ids.
This change adds Jackson 2 as an optional dependency and also provides
MappingJackson2HttpMessageConverter and MappingJackson2JsonView for use
with the new version.

The MVC namespace and the MVC Java config detect and use
MappingJackson2HttpMessageConverter if Jackson 2 is present.
Otherwise if Jackson 1.x is present,
then MappingJacksonHttpMessageConverter is used.

Issue: SPR-9302
Backport-Issue: SPR-9507
Backport-Commit: e63ca04fdb

org.springframework.web/pom.xml

@@ -124,6 +124,12 @@
       <version>1.4.2</version>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>2.0.2</version>
+      <optional>true</optional>
+    </dependency>
     <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-aop</artifactId>