1. code clean and added documentation for debugging protocol

2. upgrade to version 0.14 since I trimmed the debug message types

src/test/java/org/luaj/debug/DebugResponseTest.java

@@ -5,7 +5,6 @@ import java.io.IOException;
 import junit.framework.TestCase;
 
 import org.luaj.debug.response.DebugResponseCallgraph;
-import org.luaj.debug.response.DebugResponseSession;
 import org.luaj.debug.response.DebugResponseStack;
 import org.luaj.vm.Lua;
 
@@ -83,17 +82,4 @@ public class DebugResponseTest extends TestCase {
             assertEquals(inFrames[i], outFrames[i]);
         }
     }
-    
-    public void testDebugResponseSession() {
-        try {
-            DebugResponseSession sessionResponse = new DebugResponseSession(100);
-            byte[] data = SerializationHelper.serialize(sessionResponse);
-            DebugResponseSession sessionOut 
-                = (DebugResponseSession) SerializationHelper.deserialize(data);
-            assertNotNull(sessionOut);
-            assertEquals(sessionResponse.getSessionId(), sessionOut.getSessionId());            
-        } catch (IOException e) {
-            fail(e.getMessage());
-        }
-    }
 }

src/test/java/org/luaj/debug/EnumTypeTest.java

@@ -17,7 +17,7 @@ public class EnumTypeTest extends TestCase {
 
     public void testDebugEventTypeSerialization() {
         try {
-            DebugMessageType type = DebugMessageType.error;
+            DebugMessageType type = DebugMessageType.suspendedOnError;
             byte[] data = SerializationHelper.serialize(type);
             DebugMessageType typeOut = (DebugMessageType) SerializationHelper
                     .deserialize(data);