Fixing bug in Arc_KDTree which allowed points to be converted to XYZ multiple times.
Fixing bug in Arc_KDTree which allowed points to be converted to XYZ multiple times.

pombreda/pysal,google-code-export/pysal,google-code-export/pysal,pombreda/pysal,pombreda/pysal,pombreda/pysal,google-code-export/pysal,google-code-export/pysal