Patch D133: Python wrapper for BLI_kdtree (adds mathutils.kdtree)

Originally by Dan Eicher, with my own fixes and adjustments (see patch page for details).

For details there are unit tests and api example usage.

	doc/python_api/sphinx-in-tmp/menu_id.png

source/blender/python/mathutils/CMakeLists.txt

@@ -38,6 +38,7 @@ set(SRC
 	mathutils_Quaternion.c
 	mathutils_Vector.c
 	mathutils_geometry.c
+	mathutils_kdtree.c
 	mathutils_noise.c
 
 	mathutils.h
@@ -47,6 +48,7 @@ set(SRC
 	mathutils_Quaternion.h
 	mathutils_Vector.h
 	mathutils_geometry.h
+	mathutils_kdtree.h
 	mathutils_noise.h
 )