Changed quadtree naming scheme: Multiple levels of the quadtree can now share the same directory Regularized the naming of the root node Each leaf file is uniquely named according to position in quadtree.
Changed quadtree naming scheme:
Multiple levels of the quadtree can now share the same directory
Regularized the naming of the root node
Each leaf file is uniquely named according to position in quadtree.

Example:
Old:
  foo.qtree/foo/0/0/0/0/0/0.png
New (1 level per directory):
  foo.qtree/r/0/0/0/0/0/r000000.png
New (3 levels per directory):
  foo.qtree/r00/000/r000000.png




fengzhyuan/visionworkbench,AveRapina/visionworkbench,fengzhyuan/visionworkbench,DougFirErickson/visionworkbench,fengzhyuan/visionworkbench,DougFirErickson/visionworkbench,AveRapina/visionworkbench,fengzhyuan/visionworkbench,AveRapina/visionworkbench,AveRapina/visionworkbench,AveRapina/visionworkbench,DougFirErickson/visionworkbench,fengzhyuan/visionworkbench,DougFirErickson/visionworkbench,fengzhyuan/visionworkbench,AveRapina/visionworkbench,fengzhyuan/visionworkbench,DougFirErickson/visionworkbench,DougFirErickson/visionworkbench