Clean up warnings in spring-test

- Deleted unused imports.

 - Switched from junit.framework.Assert to org.junit.Assert, since the
   former is deprecated as of JUnit 4.11.

 - Suppressed warnings for continued deprecated usage of
   junit.framework.Assert.

spring-test-mvc/src/main/java/org/springframework/test/web/client/response/MockRestResponseCreators.java

@@ -15,15 +15,11 @@
  */
 package org.springframework.test.web.client.response;
 
-import java.io.IOException;
 import java.net.URI;
 
 import org.springframework.core.io.Resource;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
-import org.springframework.http.client.ClientHttpRequest;
-import org.springframework.mock.http.client.MockClientHttpResponse;
 import org.springframework.test.web.client.ResponseCreator;
 
 /**

spring-test/src/test/java/org/springframework/test/context/expression/ExpressionUsageTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 
 package org.springframework.test.context.expression;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import java.util.Properties;
 

spring-test/src/test/java/org/springframework/test/context/junit38/FailingBeforeAndAfterMethodsTests.java

@@ -92,6 +92,7 @@ public class FailingBeforeAndAfterMethodsTests {
 	static class AlwaysFailingBeforeTestMethodTestExecutionListener extends AbstractTestExecutionListener {
 
 		@Override
+		@SuppressWarnings("deprecation")
 		public void beforeTestMethod(TestContext testContext) {
 			junit.framework.Assert.fail("always failing beforeTestMethod()");
 		}
@@ -100,6 +101,7 @@ public class FailingBeforeAndAfterMethodsTests {
 	static class AlwaysFailingAfterTestMethodTestExecutionListener extends AbstractTestExecutionListener {
 
 		@Override
+		@SuppressWarnings("deprecation")
 		public void afterTestMethod(TestContext testContext) {
 			junit.framework.Assert.fail("always failing afterTestMethod()");
 		}