Added Intersction by Line and MultiLine capability to LayerFilters

[lossyrob]

This PR adds the ability to query a GeoTrellis layer by Line and MultiLine, much like we can already query by Polygon and MultiPolygon.

For instance,

val poly: Polygon = ???
val rdd = 
    layerReader
       .query[SpatialKey, Tile, TileLayerMetadata[SpatialKey]](Layer("name", zoom))
       .where(Intersects(poly))
       .result

will give you all tiles that intersect with the polygon, where as now

val poly: Polygon = ???
val rdd = 
    layerReader
       .query[SpatialKey, Tile, TileLayerMetadata[SpatialKey]](Layer("name", zoom))
       .where(Intersects(poly.exterior))
       .result

will give you all tiles that intersect just the exterior of the polygon.