actually fix canvas style scale adjustment this time
only send the minimum necessary tile data from worker back to main thread
minor simplification for counting GL geometries
GL geometry subclasses for triangles and points aren't needed anymore, since attributes can be specified directly now at geom creation time
add rstats for render/GL benchmarking
tesselator can optionally add a constant z coordinate
move geometry builders to render modes
move render modes to own file
includes some changes to vertex buffer construction, and commented experiments for future exploration
uniform flags should just be plain JS booleans
convenience function to recompile all shaders
fix polyline outlines z coord
update build