rm borderWidth constant, box thickness 2->3

Program.cs

@@ -297,8 +297,7 @@ public class Game : GameWindow {
     GL.BindBuffer(BufferTarget.ArrayBuffer, VertexBufferObject);
     GL.ActiveTexture(TextureUnit.Texture0);
 
-    int borderWidth = 0;
-    int maxPhotoWidth = windowWidth - thumbnailWidth - borderWidth;
+    int maxPhotoWidth = windowWidth - thumbnailWidth;
 
     Texture active = textures[textureIndex];
     // TODO: handle the case where we need to letterbox vertically instead.
@@ -308,10 +307,10 @@ public class Game : GameWindow {
 
     DrawTexture(active, letterboxWidth, 0, photoWidth, windowHeight);
     for (int i = 0; i < textures.Count; i++) {
-      Rectangle box = new Rectangle(windowWidth - thumbnailWidth, i * thumbnailHeight, thumbnailWidth, thumbnailHeight - borderWidth);
+      Rectangle box = new Rectangle(windowWidth - thumbnailWidth, i * thumbnailHeight, thumbnailWidth, thumbnailHeight);
       DrawTexture(textures[i], box);
       if (i == textureIndex) {
-        DrawBox(box, 2);
+        DrawBox(box, 3);
       }
     }