增加撤销与启动，详见：#I3ILBG

调整工程结构，采用模块化机制

Infrastructure/Const/FlowInstanceStatus.cs

@@ -0,0 +1,30 @@
+namespace Infrastructure.Const
+{
+    /// <summary>
+    /// 流程状态
+    /// </summary>
+    public struct FlowInstanceStatus
+    {
+        /// <summary>
+        /// 撤销、召回
+        /// </summary>
+        public const int Draft = -1; 
+        /// <summary>
+        /// 正在运行
+        /// </summary>
+        public const int Running = 0; 
+        /// <summary>
+        /// 完成
+        /// </summary>
+        public const int Finished = 1; 
+        /// <summary>
+        /// 不同意
+        /// </summary>
+        public const int Disagree = 3;  
+        /// <summary>
+        /// 驳回
+        /// </summary>
+        public const int Rejected = 4; 
+        
+    }
+}