Fixed Bound Calculation

To get the Bounds, the Union method of the rectangle must be called only when the first rectangle has been set. If the Renctangle is empty, use the first children's Bound, as a rectangle.

Source/Document Structure/SvgGroup.cs

@@ -47,9 +47,17 @@ namespace Svg
             	var r = new RectangleF();
             	foreach(var c in this.Children)
             	{
-            		if(c is SvgVisualElement)
+                    if (c is SvgVisualElement)
+                    {
+                    	// First it should check if rectangle is empty or it will return the wrong Bounds.
+                    	// This is because when the Rectangle is Empty, the Union method adds as if the first values where X=0, Y=0
+                        if (r.IsEmpty)
+                            r = ((SvgVisualElement)c).Bounds;
+                        else
                             r = RectangleF.Union(r, ((SvgVisualElement)c).Bounds);
                     }
+            	}
+            	
             	return r;
             }
         }