Clean up "abstract" test issues

- Deleted empty AbstractWebSocketClientTests class.

 - AbstractServletHandlerMethodTests and AbstractHttpRequestTests are
   now actually declared as abstract.

 - The following classes are not abstract but currently have an
   "Abstract" prefix and therefore get ignored by the Gradle build.
   This commit renames each of these by deleting the "Abstract" prefix.

   - AbstractFlashMapManagerTests
   - AbstractMappingContentNegotiationStrategyTests
   - AbstractSockJsServiceTests
   - AbstractWebSocketHandlerRegistrationTests

spring-web/src/test/java/org/springframework/web/accept/MappingContentNegotiationStrategyTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.web.accept;
 
 import static org.junit.Assert.assertEquals;
@@ -31,7 +32,7 @@ import org.springframework.web.context.request.NativeWebRequest;
  * @author Rossen Stoyanchev
  * @since 3.2
  */
-public class AbstractMappingContentNegotiationStrategyTests {
+public class MappingContentNegotiationStrategyTests {
 
 	@Test
 	public void resolveMediaTypes() {