Add aggregator to MGSHPositionSumFunctionRisk.

Add RMultipleValueConverter so that we can represent RMultiple as numeric in the grid while at the same time preserving the "R" which is appended to
it.

Utility/UIUtils.cs

@@ -10,6 +10,20 @@ using MarketData.Utils;
 
 namespace TradeBlotter.UIUtils
 {
+  public class RMultipleValueConverter : IValueConverter
+  {
+    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+    {
+      double doubleValue = (double)value;
+      if (double.IsNaN(doubleValue)) return Constants.CONST_DASHES;
+      return Utility.FormatNumber(doubleValue,2)+"R";
+    }
+    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+    {
+      return null;
+    }
+  }
+
   public class DoubleValueConverter : IValueConverter
   {
     public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)