Reflect @Async executor qual. 3.2=>3.1.2 backport

@Async executor qualification has been backported to 3.1.2. This commit
updates all @since tags appropriately, as well as carrying over the
changes backported to the spring-task-3.1 schema.

Issue: SPR-6847, SPR-9443

spring-context/src/main/java/org/springframework/scheduling/annotation/AnnotationAsyncExecutionInterceptor.java

@@ -26,11 +26,11 @@ import org.springframework.core.annotation.AnnotationUtils;
  * Specialization of {@link AsyncExecutionInterceptor} that delegates method execution to
  * an {@code Executor} based on the {@link Async} annotation. Specifically designed to
  * support use of {@link Async#value()} executor qualification mechanism introduced in
- * Spring 3.2. Supports detecting qualifier metadata via {@code @Async} at the method or
+ * Spring 3.1.2. Supports detecting qualifier metadata via {@code @Async} at the method or
  * declaring class level. See {@link #getExecutorQualifier(Method)} for details.
  *
  * @author Chris Beams
- * @since 3.2
+ * @since 3.1.2
  * @see org.springframework.scheduling.annotation.Async
  * @see org.springframework.scheduling.annotation.AsyncAnnotationAdvisor
  */

spring-context/src/main/java/org/springframework/scheduling/annotation/Async.java

@@ -57,7 +57,7 @@ public @interface Async {
 	 * <p>When specified on a class level {@code @Async} annotation, indicates that the
 	 * given executor should be used for all methods within the class. Method level use
 	 * of {@link Async#value} always overrides any value set at the class level.
-	 * @since 3.2
+	 * @since 3.1.2
 	 */
 	String value() default "";