add accessor for TileRenderer
fix: clear depth buffer for tile clipping
GeometryBuffer: return self for chaining, add toString()
fix: GeometryBuffer.startLine()

- *always* set end marker
add MapElement.toString()
add LwHttp constructor with additional request header items
LwHttp, ignore readers that try to close InputStream.
improve DebugTheme
add Point utilities
improve LineLayer bevel joint
LineLayer refactor:

- extract addLine()
- expand variable names
LineLayer: drop invalid lines
gradle: jts
drawing api is ready
fix drawing example
use jeo renderer
update GraphicsLayer to extends GeometryLayer
move core.geometries -> layers.vector.geometries

- rename GraphicsLayer -> VectorLayer
VectorLayer TODOs
write transformPath, fix polygon generalization