Envelope2D serialize; OperatorDistance optimized for Point to Envelope;A...

... bug in Polyline vs Polygon intersection;SimpleRasterizer for acceleration

@randallwhitman @climbage @mraad Could you test serg_some_fixes code. See if it works for you. I added serialization for Envelope2D, improved Envelope to Point distance calculation in OperatorDistance. Also, I added SimpleRasterizer that is used for the geometry acceleration (can rasterize geometry and use the raster to speed up some queries).