Move squarifiedRatio into private static function
Move makeMBR into private static function
Make minWidth and maxWidth private member variables
Move more functions into private methods
Move search and searchReturningObject into methods
Move remove into method
Move insert into method
Clean up some comments
Sort methods alphabetically
Add ol.extent.empty
Use empty extents and refactor for clarity
Merge pull request #740 from twpayne/rtree-clean-ups

R-tree clean-ups