refactor: rename RenderOverlay classes
add beginnings of BuildingOverlay
move TileGenerator from 'renderer' to 'generator' package
docs
reorder TileGenerator functions
more work on building layer
- fix roof triagulation for polygons with holes
- omit indices for outline outside tile boundaries
- add building roof outlines
- create extrusion vertices and indices in one loop
theme tweaks
add triangle jni source
clear Clipper when layer is compiled
ignore++
enable polygon offset again
add safety check...
 jni => for the real segv!
cleanup
avoid sqrt, just flip that vector
fix triangulation of complex polygons:
 find coordinates inside hole non-convex holes
update the libtriangle.so
remove binary
use glCullFace GL_FRONT to avoid having to flip triangles
triangle-jni: some loop optimizations