bug fix and unit tests for extension methods

Author: sonjakhan

src/Microsoft.Framework.Logging.Console/ConsoleLogger.cs

@@ -41,6 +41,10 @@ public void Write(LogLevel logLevel, int eventId, object state, Exception except
                     level: 1,
                     bullet: false);
                 message = builder.ToString();
+                if (exception != null)
+                {
+                    message += Environment.NewLine + exception;
+                }
             }
             else if (formatter != null)
             {

src/Microsoft.Framework.Logging/LoggerExtensions.cs

@@ -486,7 +486,7 @@ private static void Write(
             ILoggerStructure state,
             Exception exception = null)
         {
-            logger.Write(logLevel, 0, state, null, _loggerStructureFormatter);
+            logger.Write(logLevel, 0, state, exception, _loggerStructureFormatter);
         }
 
         private static void WriteWithEvent(
@@ -496,12 +496,12 @@ private static void WriteWithEvent(
             ILoggerStructure state,
             Exception exception = null)
         {
-            logger.Write(logLevel, eventId, state, null, _loggerStructureFormatter);
+            logger.Write(logLevel, eventId, state, exception, _loggerStructureFormatter);
         }
 
         private static string LoggerStructureFormatter(ILoggerStructure state, Exception exception)
         {
-            return state.Format();
+            return state.Format() + Environment.NewLine + exception;
         }
     }
 }