#683 Aggregation Template - first draft of basic dialog for merging impact summary from two layers.
#683 Aggregation Template - first draft of basic test for impact function dialog.
#683 Aggregation Template - minor updates - added first test dataset.
#701 Aggregation fails with flood impact on people - fix by stripping of thousands separator from numbers. Mbernasocci please review.
Added Akbar to the AUTHORS file.