Document programmatic HTTPD and SSHD logging configuration

Change-Id: Ie342a593a8ae854fe33f312cac22e1089119614a

gerrit-server/src/main/java/com/google/gerrit/server/util/LogUtil.java

@@ -0,0 +1,26 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.util;
+
+import com.google.common.base.Strings;
+
+public class LogUtil {
+
+  private static final String LOG4J_CONFIGURATION = "log4j.configuration";
+
+  public static boolean shouldConfigureLogSystem() {
+    return Strings.isNullOrEmpty(System.getProperty(LOG4J_CONFIGURATION));
+  }
+}