Fix lineprocessor sample and include it in the gyp build.

samples/lineprocessor.cc

Index: samples/lineprocessor.cc
diff --git a/samples/lineprocessor.cc b/samples/lineprocessor.cc
index 1606a8f99c71b72ae52a8b47d847795e9f4c00eb..7a84a2a0ffd2f29a785eafe36d071d9f7e9fcfd0 100644
--- a/samples/lineprocessor.cc
+++ b/samples/lineprocessor.cc
@@ -1,4 +1,4 @@
-// Copyright 2009 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -434,9 +434,9 @@ v8::Handle<v8::String> ReadLine() {
   }
   if (res == NULL) {
     v8::Handle<v8::Primitive> t = v8::Undefined();
-    return reinterpret_cast<v8::Handle<v8::String>&>(t);
+    return v8::Handle<v8::String>(v8::String::Cast(*t));
   }
-  // remove newline char
+  // Remove newline char
   for (char* pos = buffer; *pos != '\0'; pos++) {
     if (*pos == '\n') {
       *pos = '\0';