Move child process to extension model.

src/node.cc

@@ -1597,10 +1597,6 @@ static Handle<Value> Binding(const Arguments& args) {
     StatWatcher::Initialize(exports);
     File::Initialize(exports);
     binding_cache->Set(module, exports);
-  } else if (!strcmp(*module_v, "child_process")) {
-    exports = Object::New();
-    ChildProcess::Initialize(exports);
-    binding_cache->Set(module, exports);
   } else if (!strcmp(*module_v, "buffer")) {
     exports = Object::New();
     Buffer::Initialize(exports);

src/node_child_process.cc

@@ -332,3 +332,5 @@ int ChildProcess::Kill(int sig) {
 }
 
 }  // namespace node
+
+NODE_MODULE(node_child_process, node::ChildProcess::Initialize);

src/node_extensions.h

@@ -1,6 +1,7 @@
 
 NODE_EXT_LIST_START
 NODE_EXT_LIST_ITEM(node_cares)
+NODE_EXT_LIST_ITEM(node_child_process)
 #ifdef HAVE_OPENSSL
 NODE_EXT_LIST_ITEM(node_crypto)
 #endif