修改了http服务器无法正确处理post请求入参；添加了modbus tcp客户端支持。

Library/Network/Modbus/ModbusFunctionCode.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Serein.Library.Network.Modbus
+{
+    /// <summary>
+    /// Modbus 功能码枚举
+    /// </summary>
+    public enum ModbusFunctionCode
+    {
+        /// <summary>
+        /// 读线圈
+        /// </summary>
+        ReadCoils = 0x01,
+        /// <summary>
+        /// 读离散输入
+        /// </summary>
+        ReadDiscreteInputs = 0x02,
+        /// <summary>
+        /// 读保持寄存器
+        /// </summary>
+        ReadHoldingRegisters = 0x03,
+        /// <summary>
+        /// 读输入寄存器
+        /// </summary>
+        ReadInputRegisters = 0x04,
+        /// <summary>
+        /// 写单个线圈
+        /// </summary>
+        WriteSingleCoil = 0x05,
+        /// <summary>
+        /// 写单个寄存器
+        /// </summary>
+        WriteSingleRegister = 0x06,
+        /// <summary>
+        /// 写多个线圈
+        /// </summary>
+        WriteMultipleCoils = 0x0F,
+        /// <summary>
+        /// 写多个寄存器
+        /// </summary>
+        WriteMultipleRegister = 0x10,
+    }
+}