Changes made for the following:

1) Platform.java stays as abstract class with, but default implementation is removed. Stays in org.luaj.vm package
2) org.luaj.platform package is created to hold concrete Platform implementations
3) Platform.newLuaState() method is introduced to instantiate the LuaState. Other constructors are privatized.
4) Following Platform implementations are created:
        J2sePlatform
        J2meMidp20Cldc11Platform
        J2meMidp10Cldc10Platform
 5) All clients of luaj-vm are changed to include startup code that looks something like this:
        Platform.setInstance( new J2meMidp20Cldc11Platform() );
        LuaState state = Platform.getInstance().newLuaState();

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

@@ -24,21 +24,33 @@ package org.luaj.debug;
 import java.io.IOException;
 import java.io.InputStream;
 
-import org.luaj.debug.DebugLuaState;
+import junit.framework.TestCase;
+
+import org.luaj.TestPlatform;
+import org.luaj.compiler.LuaC;
+import org.luaj.vm.DebugNetSupport;
 import org.luaj.vm.LClosure;
+import org.luaj.vm.LPrototype;
 import org.luaj.vm.LValue;
 import org.luaj.vm.LoadState;
-import org.luaj.vm.LPrototype;
-
-import junit.framework.TestCase;
+import org.luaj.vm.LuaState;
+import org.luaj.vm.Platform;
 
 public class DebugStackStateTest extends TestCase {
 
 	public void testDebugStackState() throws InterruptedException, IOException {
-		String script = "/test6.luac";
+		String script = "/test6.lua";
 		
 		// set up the vm
-		final DebugLuaState state = new DebugLuaState();
+		System.setProperty(Platform.PROPERTY_LUAJ_DEBUG, "true");
+		Platform.setInstance(new TestPlatform() {
+		    public DebugNetSupport getDebugSupport() throws IOException {
+		        return null;
+		    }
+		});
+
+		final DebugLuaState state = (DebugLuaState) Platform.newLuaState();
+                LuaC.install();
 		InputStream is = getClass().getResourceAsStream( script );
 		LPrototype p = LoadState.undump(state, is, script);