Make tile range calculation consistent

When a tile grid determines the tile for a given coordinate and resolution, edge intersections go to the higher x/y tile coord.  Because the methods to get a tile range for an extent use this same logic, it gives the tile range an inconsistent meaning.  When the top-left corner of the provided range intersects a tile boundary, we get a range that is exclusive in its max x/y values.  When the top-left corner doesn't intersect a tile boundary, we get a range that is inclusive in its max x/y values.