Add option in GridViewDocumentExportOptions to include / exclude GroupHeaderRowAggregates.

This will allow users to hide/show group header row aggregates in the exported documents.

Option will be globbally applied - to all group header rows in the RadGridView.
===
From 2017 R3 SP GridViewDocumentExportOptions  adds ShowGroupHeaderRowAggregates bool property.

It can be used like so:

  GridViewDocumentExportOptions options = new GridViewDocumentExportOptions()
            {
                ShowGroupHeaderRowAggregates = true
            };
this.gridView.ExportToWorkbook(options);

Available in LIB version: 2017.2.724

The problem should be resolved with lib version 2016.1.125.

When I have DistinctFilter set on the grid and I will search data from SearchPanel and then I will clear SearchPanel, Grid show me all data, not these from DistinctFilter, even if it's still set on the grid.

UI for WPF Q1 2016

This functionality will be available with Q1 2016 SP.

Will be available with LIB version 2015.3.1026.