Don't pick the boundaries as split points in kdtree

Status Job ID Name Coverage
  External
passed cdash

passed diy-dejagore-linux-debug+clang3.8+openmpi1.10.2+threads

00:02:58

passed diy-dejagore-linux-release+gcc5+openmpi2.1.3+threads

00:01:38

passed diy-dejagore-linux-release+gcc5+threads

00:01:36

passed diy-dragnipur-osx-release+clang+mpich3.2.1+threads

00:01:24

passed diy-dragnipur-osx-release+clang+openmpi3.0.0+threads

00:01:22

passed diy-osheim-windows-debug+threads+vs2017

00:06:34

passed diy-osheim-windows-release+threads+vs2017

00:03:34

passed diy-renar-linux-release+gcc6+threads

00:01:19

passed diy-renar-linux-release+gcc7+mpich3.2.1

00:01:21

passed ghostflow-check-master