Issue #434 RequestTest stack traces

Added reset to ShutdownMonitor

jetty-server/src/main/java/org/eclipse/jetty/server/ShutdownMonitor.java

@@ -64,6 +64,11 @@ public class ShutdownMonitor
         return Holder.instance;
     }
 
+    protected static void reset()
+    {
+        Holder.instance = new ShutdownMonitor();
+    }
+    
     public static void register(LifeCycle... lifeCycles)
     {
         getInstance().addLifeCycles(lifeCycles);

jetty-server/src/test/java/org/eclipse/jetty/server/ShutdownMonitorTest.java

@@ -26,6 +26,7 @@ import java.net.InetAddress;
 import java.net.Socket;
 
 import org.eclipse.jetty.util.thread.ShutdownThread;
+import org.junit.AfterClass;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
@@ -33,6 +34,12 @@ import static org.junit.Assert.assertTrue;
 
 public class ShutdownMonitorTest
 {
+    @AfterClass
+    public static void afterClass()
+    {
+        ShutdownMonitor.reset();
+    }
+    
     @Test
     public void testShutdownMonitor() throws Exception
     {