Normalize grid to a cell size
10-12x faster tree build
Add Tests target and first annotation tree integrity test
Extract buildTree into a C function
Add annotation tree equivalence test
Inline buildTree(), annotate tree building functions
Merge pull request #20 from stanislaw/faster_tree_build

10-12x faster tree build
Merge commit '5b6029f441fa4984662a6dc4568cd1d21ffed337'

* commit '5b6029f441fa4984662a6dc4568cd1d21ffed337':
  Inline buildTree(), annotate tree building functions
  Add annotation tree equivalence test
  Extract buildTree into a C function
  Add Tests target and first annotation tree integrity test
  10-12x faster tree build
  Normalize grid to a cell size