Fix bug in transport_tcp (ros#1050)

* Fix bug in transport_tcp

It assumes that the `connect` method of non-blocking scoket should return -1 and `last_socket_error()` should return `ROS_SOCKETS_ASYNCHRONOUS_CONNECT_RETURN`(=`EINPROGRESS`). 
But a non-blocking `connect` can return 0 when TCP connection to 127.0.0.1 (localhost).
[http://stackoverflow.com/questions/14027326/can-connect-return-0-with-non-blocing-socket](http://stackoverflow.com/questions/14027326/can-connect-return-0-with-non-blocing-socket)

* Modify code format

Modify code format

clients/roscpp/src/libros/transport/transport_tcp.cpp

@@ -312,9 +312,10 @@ bool TransportTCP::connect(const std::string& host, int port)
 
   int ret = ::connect(sock_, (sockaddr*) &sas, sas_len);
   // windows might need some time to sleep (input from service robotics hack) add this if testing proves it is necessary.
-  ROS_ASSERT((flags_ & SYNCHRONOUS) || ret != 0);
+  // ROS_ASSERT((flags_ & SYNCHRONOUS) || ret != 0);
   if (((flags_ & SYNCHRONOUS) && ret != 0) || // synchronous, connect() should return 0
-      (!(flags_ & SYNCHRONOUS) && last_socket_error() != ROS_SOCKETS_ASYNCHRONOUS_CONNECT_RETURN)) // asynchronous, connect() should return -1 and WSAGetLastError()=WSAEWOULDBLOCK/errno=EINPROGRESS
+      (!(flags_ & SYNCHRONOUS) && ret != 0 && last_socket_error() != ROS_SOCKETS_ASYNCHRONOUS_CONNECT_RETURN)) 
+      // asynchronous, connect() may return 0 or -1. When return -1, WSAGetLastError()=WSAEWOULDBLOCK/errno=EINPROGRESS
   {
     ROSCPP_CONN_LOG_DEBUG("Connect to tcpros publisher [%s:%d] failed with error [%d, %s]", host.c_str(), port, ret, last_socket_error_string());
     close();