[#qGyzXbjp] Adds the GeoShapeRelationCalculator.
[#qGyzXbjp] Adds the Polygon with evil powers.
[#qGyzXbjp] Renames GeoShapeRelationCalculator.
[#qGyzXbjp] Renames GeoShapeRelationCalculator::Polygon.
[#qGyzXbjp] Makes sure intersection_area is a float before division.
[#qGyzXbjp] Fixes wording according to PR comments.
Merge branch 'polygon_qGyzXbjp'
Merge branch 'relation_calculator_qGyzXbjp'