Ball Tree, KD Tree, and tests
Fix tests for scipy <= 0.9
speed up KD tree construction by ~25%
add author & license information to pyx files
add median of 3 pivoting to quicksort
add pydist code
fix binary tree sort bug
add pydist: user-defined metric
add haversine distance
add exception passing to C functions
rename dist conversion funcs
Implement correct d-dimensional kernel norms
add metric mappings to dist_metrics
binary tree: make valid_metrics a class variable
dist_metrics: allow callable metric
add chebyshev distance to kd tree
add functionality to NearestNeighbors estimators
Roger-Stanimoto -> Rogers-Tanimoto
calculate kernel norm only once
compute kernel norm only once