Reflect 3.2=>3.1.2 backports in @since tags etc

Issue: SPR-9443, SPR-6847, SPR-9446, SPR-9444, SPR-9439, SPR-9302,
       SPR-9507, SPR-9238, SPR-9397, SPR-9406, SPR-9502

spring-core/src/main/java/org/springframework/core/env/ConfigurableEnvironment.java

@@ -164,7 +164,7 @@ public interface ConfigurableEnvironment extends Environment, ConfigurableProper
 	 * reflected in the child. Therefore, care should be taken to configure parent
 	 * property sources and profile information prior to calling {@code merge}.
 	 * @param parent the environment to merge with
-	 * @since 3.2
+	 * @since 3.1.2
 	 * @see org.springframework.context.support.AbstractApplicationContext#setParent
 	 */
 	void merge(ConfigurableEnvironment parent);