Introduce @EnableSpringConfigured

Equivalent to <context:spring-configured/>.

Also update @EnableLoadTimeWeaving Javadoc and spring-configured XSD
documentation to reflect.

Issue: SPR-7888

org.springframework.context/src/main/java/org/springframework/context/annotation/EnableLoadTimeWeaving.java

@@ -117,8 +117,8 @@ import org.springframework.instrument.classloading.LoadTimeWeaver;
  * <p>The two examples are equivalent with one significant exception: in the XML case,
  * the functionality of {@code <context:spring-configured>} is implicitly enabled when
  * {@code aspectj-weaving} is "on".  This does not occur when using
- * {@code @EnableLoadTimeWeaving(aspectjWeaving=ENABLED)}, although this may change in
- * future revisions.
+ * {@code @EnableLoadTimeWeaving(aspectjWeaving=ENABLED)}. Instead you must explicitly add
+ * {@code @EnableSpringConfigured} (included in the {@code spring-aspects} module)
  *
  * @author Chris Beams
  * @since 3.1

org.springframework.context/src/main/resources/org/springframework/context/config/spring-context-3.1.xsd

@@ -360,6 +360,10 @@
 	Signals the current application context to apply dependency injection
 	to non-managed classes that are instantiated outside of the Spring bean
 	factory (typically classes annotated with the @Configurable annotation).
+
+	See Javadoc for org.springframework.context.annotation.EnableSpringConfigured in the
+	spring-aspects module for information on code-based alternatives to bootstrapping
+	this functionality.
 			]]></xsd:documentation>
 		</xsd:annotation>
 		<xsd:simpleType>