Add ol.geom.flat.segments#forEach
Add ol.geom.flat.intersects

Includes functions for testing if an extent and a linestring intersect, if an extent and a linear ring intersect, if an extent and a polygon intersect, and if an extent and a multi-polygon intersect.
Add ol.geom.Polygon#intersectsExtent
Add ol.geom.MultiPolygon#intersectsExtent
Add a box feature selection example