Added command line debugger to D8 shell....

src/d8.h

Index: src/d8.h
===================================================================
--- src/d8.h	(revision 993)
+++ src/d8.h	(working copy)
@@ -88,12 +88,17 @@
   static int Main(int argc, char* argv[]);
   static Handle<Array> GetCompletions(Handle<String> text,
                                       Handle<String> full);
+  static Handle<String> DebugEventToText(Handle<Object> event);
+  static Handle<Value> DebugCommandToJSONRequest(Handle<String> command);
+  static Handle<Object> DebugResponseDetails(Handle<String> response);
 
   static Handle<Value> Print(const Arguments& args);
   static Handle<Value> Quit(const Arguments& args);
   static Handle<Value> Version(const Arguments& args);
   static Handle<Value> Load(const Arguments& args);
 
+  static Handle<Context> utility_context() { return utility_context_; }
+
   static const char* kHistoryFileName;
   static const char* kPrompt;
  private: