Upgrade Log4j to current 2.15.0 version.

(cherry picked from commit d0bac56c)

pom.xml

@@ -150,12 +150,24 @@
 			<version>1.4</version>
 		</dependency>
 
-		<!-- Logging -->		
+			
+		<!-- Logging with Log4j -->
+		<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
+		<dependency>
+		    <groupId>org.apache.logging.log4j</groupId>
+		    <artifactId>log4j-core</artifactId>
+		    <version>2.15.0</version>
+		</dependency>
+		
+		<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api -->
 		<dependency>
-			<groupId>log4j</groupId>
-			<artifactId>log4j</artifactId>
-			<version>1.2.16</version>
+		    <groupId>org.apache.logging.log4j</groupId>
+		    <artifactId>log4j-api</artifactId>
+		    <version>2.15.0</version>
 		</dependency>
+
+		
+		
 		<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
 		<dependency>
 		    <groupId>org.slf4j</groupId>

src/de/tud/kom/p2psim/impl/common/DefaultMonitor.java

@@ -29,7 +29,8 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
-import org.apache.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import de.tud.kom.p2psim.api.simengine.SimulatorObserver;
 import de.tud.kom.p2psim.impl.simengine.Simulator;
@@ -94,7 +95,7 @@ public class DefaultMonitor implements MonitorComponent, EventHandler,
 	public void log(Class<?> subject, Level level, String msg, Object... data) {
 		Logger log = loggers.get(subject);
 		if (log == null) {
-			log = Logger.getLogger(subject);
+			log = LogManager.getLogger(subject);
 			loggers.put(subject, log);
 		}
 		switch (level) {

src/de/tud/kom/p2psim/impl/scenario/simcfg2/utils/SimCfgExpressionExecutor.java

@@ -20,7 +20,9 @@
 package de.tud.kom.p2psim.impl.scenario.simcfg2.utils;
 
 import de.tud.kom.p2psim.impl.scenario.simcfg2.configuration.SimCfgConfiguration;
-import org.apache.log4j.Logger;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import javax.script.*;
 import java.util.Map;
@@ -30,7 +32,7 @@ import java.util.Map;
  * @version 1.0, 12.07.13
  */
 public class SimCfgExpressionExecutor {
-    private static final Logger log = Logger.getLogger(SimCfgExpressionExecutor.class);
+    private static final Logger log = LogManager.getLogger(SimCfgExpressionExecutor.class);
     private ScriptEngine javascriptEngine = null;
 
     public SimCfgExpressionExecutor() {