Handle multiple stop limits in the stop limit table and display them properly.

Model/StopLimitCompositeModel.cs

@@ -34,7 +34,7 @@ namespace TradeBlotter.Model
       List<DateTime> stopLimitDates = new List<DateTime>();
       foreach(StopLimit stopLimit in stopLimits)
       {
-        stopLimitDates.Add(stopLimit.EffectiveDate);
+        stopLimitDates.Add(xSource);
       }
       var xData=new EnumerableDataSource<DateTime>(stopLimitDates.Select(x => x.Date));
       xData.SetXMapping(x => (x.Ticks/10000000000.0));