Fixing behavior of logback-access in the modern era

+ Fixes LOGBACK-1580 to report the proper
  HttpServletResponse.getStatus() that was used
  when the response was committed.
+ Works around LOGBACK-1581 in AccessEvent to
  not fail logging when the
    HttpServletRequest.getParameterNames() or
    HttpServletRequest.getParameter(String)
  methods are used against unread or even bad
  request objects.
+ Updated Javadoc (needs to be copied over
  to logback manual though)
+ Must use OpenJDK 1.8 to compile and release.
+ Still compiles to Java 1.6 bytecode for release.

logback-access/src/main/java/ch/qos/logback/access/jetty/JettyModernServerAdapter.java

@@ -0,0 +1,66 @@
+/**
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+package ch.qos.logback.access.jetty;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import ch.qos.logback.access.spi.ServerAdapter;
+import org.eclipse.jetty.http.HttpField;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.Response;
+
+/**
+ * A Jetty 9.4.x and 10.0.x specific implementation of the {@link ServerAdapter} interface.
+ *
+ * @author Sébastien Pennec
+ * @author Ceki Gulcu
+ * @author Joakim Erdfelt
+ */
+public class JettyModernServerAdapter extends JettyServerAdapter
+{
+    public JettyModernServerAdapter(Request jettyRequest, Response jettyResponse) {
+        super(jettyRequest, jettyResponse);
+    }
+
+    @Override
+    public long getContentLength() {
+        return response.getHttpChannel().getBytesWritten();
+    }
+
+    @Override
+    public int getStatusCode() {
+        return response.getCommittedMetaData().getStatus();
+    }
+
+    @Override
+    public long getRequestTimestamp() {
+        return request.getTimeStamp();
+    }
+
+    @Override
+    public Map<String, String> buildResponseHeaderMap() {
+        Map<String, String> responseHeaderMap = new HashMap<String, String>();
+        Iterator<HttpField> httpFieldIter = response.getHttpFields().iterator();
+        while (httpFieldIter.hasNext()) {
+            HttpField httpField = httpFieldIter.next();
+            String key = httpField.getName();
+            String value = httpField.getValue();
+            responseHeaderMap.put(key, value);
+        }
+        return responseHeaderMap;
+    }
+
+}