Added many needed readonly keywords

Advanced Software Engineering/Advanced Software Engineering Tests/ValueHelperTester.cs

@@ -9,7 +9,7 @@ namespace Advanced_Software_Engineering_Tests {
     /// </summary>
     [TestClass]
     internal class ValueHelperTester {
-        private Random rand = new Random();
+        private readonly Random rand = new Random();
 
         /// <summary>
         /// Random <see cref="ValueHelper.ConvertToInt(string)"/> test.

Advanced Software Engineering/Advanced Software Engineering/Commander.cs

@@ -10,7 +10,7 @@ namespace Advanced_Software_Engineering {
     public class Commander {
         private Graphics graphics;
         private List<IVerb> commands = new List<IVerb>();
-        private Drawer drawer;
+        private readonly Drawer drawer;
         private bool commands_ok = true;
 
         /// <summary>

Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Circle.cs

@@ -4,7 +4,7 @@
     /// Circle IVerb class.
     /// </summary>
     public class Circle : IVerb {
-        private Drawer drawer;
+        private readonly Drawer drawer;
         private double scale;
 
         /// <summary>

Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Dot.cs

@@ -4,7 +4,7 @@
     /// The Dot IVerb class
     /// </summary>
     public class Dot : IVerb {
-        private Drawer drawer;
+        private readonly Drawer drawer;
 
         /// <summary>
         /// Creates the Dot IVerb

Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/DrawLines.cs

@@ -6,10 +6,10 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// DrawLines IVerb class
     /// </summary>
     public class DrawLines : IVerb {
-        private Drawer drawer;
-        private Point[] points;
+        private readonly Drawer drawer;
+        private readonly Point[] points;
 
-        private bool descCreated = false;
+        private readonly bool descCreated = false;
         private string desc;
 
         /// <summary>

Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/DrawTo.cs

@@ -6,8 +6,8 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// DrawTo IVerb class
     /// </summary>
     public class DrawTo : IVerb {
-        private Drawer drawer;
-        private Point moveToPoint;
+        private readonly Drawer drawer;
+        private readonly Point moveToPoint;
 
         /// <summary>
         /// Creates the DrawTo intstance

Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/RegularPolygon.cs

@@ -8,11 +8,11 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// A class that generates a RegularPolygon IVerb.
     /// </summary>
     public class RegularPolygon : IVerb {
-        private Drawer drawer;
-        private int sides;
-        private double scale;
-        private double offset;
-        private List<Point> points;
+        private readonly Drawer drawer;
+        private readonly int sides;
+        private readonly double scale;
+        private readonly double offset;
+        private readonly List<Point> points;
 
         /// <summary>
         /// Draws a regular polygon.

Advanced Software Engineering/Advanced Software Engineering/Windows/ErrorWindow.cs

@@ -9,7 +9,7 @@ namespace Advanced_Software_Engineering {
     /// The error window that can show errors, warnings and messages.
     /// </summary>
     public partial class ErrorWindow : Form {
-        private string desc;
+        private readonly string desc;
 
         /// <summary>
         /// The error message type.