ipcpipeline: fix crash and error on windows with SOCKET or _pipe()
The fd was in different meanings on windows:
- POSIX read and write use the fd as a file descriptor.
- The gst_poll use the fd as a WSASocket.
This patch use WSASocket as default on windows. This is a temporary measure, because IPC has many different implement. There may be a better way in the future.
See #1044