minor cleanup
add bulk loading bench test
new benchmarks
bench updates
use partition sort for much faster bulk load
convert methods to functions, massive speedup
convert calcBBox & distBBox to functions
optimize hidden classes, cleanup
fix tests
make perf.js work again
update readme and bump version
cleanup leftover code
Merge pull request #26 from mourner/partition

Significant performance improvement
cleanup, comments
update references
improve bulk insertion by using Floyd-Rivest selection
use binary divide & conquer for select algorithm
fix tests
update readme and bump version
better viz (retina and consistent colors)