Move Windows-specific projects into separate solution.

src/Triangle.Rendering.GDI/Helper.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using System.Drawing;
+
+namespace TriangleNet.Rendering.GDI
+{
+    internal class Helper
+    {
+        public static void Dispose(Dictionary<int, SolidBrush> brushes)
+        {
+            foreach (var brush in brushes.Values)
+            {
+                brush.Dispose();
+            }
+        }
+
+        public static Dictionary<int, SolidBrush> GetBrushDictionary(Dictionary<int, Color> ColorDictionary)
+        {
+            var brushes = new Dictionary<int, SolidBrush>();
+
+            foreach (var item in ColorDictionary)
+            {
+                brushes.Add(item.Key, new SolidBrush(item.Value));
+            }
+
+            return brushes;
+        }
+    }
+}