Add options to configure content negotiation

The MVC Java config and the MVC namespace now support options to
configure content negotiation. By default both support checking path
extensions first and the "Accept" header second. For path extensions
.json, .xml, .atom, and .rss are recognized out of the box if the
Jackson, JAXB2, or Rome libraries are available. The ServletContext
and the Java Activation Framework may be used as fallback options
for path extension lookups.

Issue: SPR-8420

spring-webmvc/src/test/resources/org/springframework/web/servlet/config/mvc-config-content-negotiation-manager.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:mvc="http://www.springframework.org/schema/mvc"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
+		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
+
+	<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager" />
+
+	<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManager">
+		<constructor-arg>
+			<list>
+				<ref bean="pathExtensionStrategy" />			
+				<ref bean="headerStrategy" />			
+			</list>
+		</constructor-arg>
+	</bean>
+
+	<bean id="pathExtensionStrategy" class="org.springframework.web.accept.PathExtensionContentNegotiationStrategy">
+		<constructor-arg>
+			<map>
+				<entry key="xml" value="application/rss+xml" />
+			</map>
+		</constructor-arg>
+	</bean>
+	
+	<bean id="headerStrategy" class="org.springframework.web.accept.HeaderContentNegotiationStrategy" />
+
+</beans>