improvement on the POPClient class

[Wilson Chan]

adding ReceiveBufferSize,ReceiveTimeOut,SendBufferSize,SendTimeOut are prfered:

        private int _receiveTimeOut=5000;
        private int _sendTimeOut=5000;
        private int _receiveBufferSize=1024*50;
        private int _sendBufferSize=1024*50;

        public int ReceiveTimeOut
        {
            get
            {
                return _receiveTimeOut;
            }
            set
            {
                _receiveTimeOut=value;
            }
        }

        public int SendTimeOut
        {
            get
            {
                return _sendTimeOut;
            }
            set
            {
                _sendTimeOut=value;
            }
        }

        public int ReceiveBufferSize
        {
            get
            {
                return _receiveBufferSize;
            }
            set
            {
                _receiveBufferSize=value;
            }
        }

        public int SendBufferSize
        {
            get
            {
                return _sendBufferSize;
            }
            set
            {
                _sendBufferSize=value;
            }
        }

        public void Connect(string host,int port)
        {
            clientSocket=new TcpClient();
            clientSocket.ReceiveTimeout=_receiveTimeOut;
            clientSocket.SendTimeout=_sendTimeOut;
            clientSocket.ReceiveBufferSize=_receiveBufferSize;
            clientSocket.SendBufferSize=_sendBufferSize;
}