Made objects serializable so they work with winforms UI

PepLib/Machine.cs

@@ -1,5 +1,8 @@
-namespace PepLib
+using System;
+
+namespace PepLib
 {
+    [Serializable]
     public class Machine
     {
         public int Id { get; set; }

PepLib/Material.cs

@@ -1,5 +1,8 @@
-namespace PepLib
+using System;
+
+namespace PepLib
 {
+    [Serializable]
     public class Material
     {
         public int Id { get; set; }

PepLib/Part.cs

@@ -2,6 +2,7 @@
 
 namespace PepLib
 {
+    [Serializable]
     public class Part : IMovable
     {
         private Loop baseLoop;

PepLib/Plate.cs

@@ -4,6 +4,7 @@ using System.Linq;
 
 namespace PepLib
 {
+    [Serializable]
     public class Plate : IMovable
     {
         public Plate()

PepLib/Size.cs

@@ -1,5 +1,8 @@
-namespace PepLib
+using System;
+
+namespace PepLib
 {
+    [Serializable]
     public class Size
     {
         public Size(double height, double width)

PepLib/Spacing.cs

@@ -1,6 +1,9 @@
 
+using System;
+
 namespace PepLib
 {
+    [Serializable]
     public class Spacing
     {
         public Spacing()