Merge branch '5.3.x'

# Conflicts:
#	build.gradle
#	spring-test/src/main/java/org/springframework/mock/web/MockHttpServletRequest.java
#	spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java
#	spring-web/src/testFixtures/java/org/springframework/web/testfixture/servlet/MockHttpServletRequest.java
#	spring-web/src/testFixtures/java/org/springframework/web/testfixture/servlet/MockHttpServletResponse.java

build.gradle

@@ -71,7 +71,7 @@ configure([rootProject] + javaProjects) { project ->
 	}
 
 	checkstyle {
-		toolVersion = "10.3.4"
+		toolVersion = "10.4"
 		configDirectory.set(rootProject.file("src/checkstyle"))
 	}