Add an option for Debian packaging
Add an option for Debian packaging

If PYTHON_DEB_ROOT is set, Python 2 and Python 3 bindings will be
installed using the deb install layout and PYTHON_DEB_ROOT as root.

jrl-umi3218/SpaceVecAlg,jrl-umi3218/SpaceVecAlg,jrl-umi3218/SpaceVecAlg