fixes #518 - Add api param for watched indicator on images

MediaBrowser.Server.Implementations/Drawing/WatchedIndicatorDrawer.cs

@@ -0,0 +1,33 @@
+using System.Drawing;
+
+namespace MediaBrowser.Server.Implementations.Drawing
+{
+    public class WatchedIndicatorDrawer
+    {
+        private const int IndicatorHeight = 50;
+        private const int FontSize = 50;
+
+        public void Process(Graphics graphics, Size imageSize)
+        {
+            var x = imageSize.Width - IndicatorHeight;
+
+            using (var backdroundBrush = new SolidBrush(Color.FromArgb(225, 204, 51, 51)))
+            {
+                graphics.FillRectangle(backdroundBrush, x, 0, IndicatorHeight, IndicatorHeight);
+
+                const string text = "a";
+
+                x = imageSize.Width - 55;
+
+                using (var font = new Font("Webdings", FontSize, FontStyle.Regular, GraphicsUnit.Pixel))
+                {
+                    using (var fontBrush = new SolidBrush(Color.White))
+                    {
+                        graphics.DrawString(text, font, fontBrush, x, -2);
+                    }
+                }
+            }
+
+        }
+    }
+}