Issue #5137 - Cleanup of WebAppContextTest

+ Cleanup of test-servlet-spec webapp
+ Removing unused methods
+ Commented System.err.println moved to java.util.logging
+ General checkstyle cleanup (empty lines, spacing, etc)
+ Eliminate bogus WebApp LIB ordering tests.
+ No ClassLoader has a order guarantee.
+ Moving HttpSessionListenerTest contents to existing SessionListenerTest
+ Cleanup of SessionListenerTest with eye to resource cleanup
+ Removing ServletContextListenerTest as it duplicates tests
+ Restoring WebAppClassLoaderTest test method
+ `ordering()` is now `testClashingResource()` and properly
  tests assumptions when dealing with a ClassLoader.
  The old test assumed guaranteed order from a ClassLoader,
  which is not a feature of any Java ClassLoader.
  Especially so for URLClassLoader.
+ Restoring clashing resource test

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>

jetty-webapp/pom.xml

@@ -69,6 +69,13 @@
       <version>${project.version}</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.eclipse.jetty</groupId>
+      <artifactId>jetty-http</artifactId>
+      <version>${project.version}</version>
+      <classifier>tests</classifier>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.eclipse.jetty.toolchain</groupId>
       <artifactId>jetty-test-helper</artifactId>

jetty-webapp/src/test/java/org/eclipse/jetty/webapp/WebAppClassLoaderTest.java

@@ -342,7 +342,7 @@ public void testResources() throws Exception
     }
 
     @Test
-    public void ordering() throws Exception
+    public void testClashingResource() throws Exception
     {
         // The existence of a URLStreamHandler changes the behavior
         assumeTrue(URLStreamHandlerUtil.getFactory() == null, "URLStreamHandler changes behavior, skip test");