Slight cleanup across DatFile formats

SabreTools.DatFiles/Formats/Hashfile.cs

@@ -231,6 +231,36 @@ namespace SabreTools.DatFiles.Formats
         }
     }
 
+    /// <summary>
+    /// Represents an MD2 hashfile
+    /// </summary>
+    internal sealed class Md2File : Hashfile
+    {
+        /// <summary>
+        /// Constructor designed for casting a base DatFile
+        /// </summary>
+        /// <param name="datFile">Parent DatFile to copy from</param>
+        public Md2File(DatFile? datFile) : base(datFile)
+        {
+            _hash = HashType.MD2;
+        }
+    }
+
+    /// <summary>
+    /// Represents an MD4 hashfile
+    /// </summary>
+    internal sealed class Md4File : Hashfile
+    {
+        /// <summary>
+        /// Constructor designed for casting a base DatFile
+        /// </summary>
+        /// <param name="datFile">Parent DatFile to copy from</param>
+        public Md4File(DatFile? datFile) : base(datFile)
+        {
+            _hash = HashType.MD4;
+        }
+    }
+
     /// <summary>
     /// Represents an MD5 hashfile
     /// </summary>

SabreTools.DatFiles/Formats/Missfile.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Text;
 using SabreTools.DatItems;