Merge branch 'Fix-ClipUnstructuredGrid2' into 'master'

src/Cxx/UnstructuredGrid/ClipUnstructuredGridWithPlane2.cxx

src/Cxx/UnstructuredGrid/ClipUnstructuredGridWithPlane2.md

...Python/UnstructuredGrid/ClipUnstructuredGridWithPlane2.md

...Python/UnstructuredGrid/ClipUnstructuredGridWithPlane2.py

...onicAPI/UnstructuredGrid/ClipUnstructuredGridWithPlane.py

...nicAPI/UnstructuredGrid/ClipUnstructuredGridWithPlane2.md

...nicAPI/UnstructuredGrid/ClipUnstructuredGridWithPlane2.py

...x/UnstructuredGrid/TestClipUnstructuredGridWithPlane2.png

...UnstructuredGrid/TestClipUnstructuredGridWithPlane2_1.png

...n/UnstructuredGrid/TestClipUnstructuredGridWithPlane2.png

...UnstructuredGrid/TestClipUnstructuredGridWithPlane2_1.png

...I/UnstructuredGrid/TestClipUnstructuredGridWithPlane2.png

...UnstructuredGrid/TestClipUnstructuredGridWithPlane2_1.png