Fix thread pool unref issue.

Tests were silently failing since f56309d...

Since the eio_watcher is now not counted in the list of active watchers, we
need to explicitly tell the ev_loop not to exit when entering the thread
pool.

src/file.cc

@@ -34,7 +34,8 @@ using namespace node;
     Local<Function> l = Local<Function>::Cast(last_arg);              \
     callback = new Persistent<Function>();                            \
     *callback = Persistent<Function>::New(l);                         \
-  }
+  }                                                                   \
+  ev_ref(EV_DEFAULT_UC);
 
 #define CALL_CALLBACK_PTR(req, argc, argv)                            \
 do {                                                                  \
@@ -47,6 +48,7 @@ do {                                                                  \
       node::FatalException(try_catch);                                \
     delete callback;                                                  \
   }                                                                   \
+  ev_unref(EV_DEFAULT_UC);                                            \
 } while(0)
 
 #define DEFINE_SIMPLE_CB(name)                                        \

src/net.cc

@@ -212,6 +212,8 @@ Connection::Connect (const Arguments& args)
 
   connection->opening = true;
 
+  ev_ref(EV_DEFAULT_UC);
+  
 #ifdef __APPLE__
   /* HACK: Bypass the thread pool and do it sync on Macintosh.
    * Experiecing strange error where execution halts on 
@@ -273,6 +275,8 @@ AddressDefaultToIPv4 (struct addrinfo *address_list)
 int
 Connection::AfterResolve (eio_req *req)
 {
+  ev_unref(EV_DEFAULT_UC);
+
   Connection *connection = static_cast<Connection*> (req->data);
   struct addrinfo *address = NULL,
                   *address_list = static_cast<struct addrinfo *>(req->ptr2);