all: change license to be BSD-2-Clause

CMakeLists.txt

COPYING.LESSER

include/eigenpy/angle-axis.hpp

include/eigenpy/details.hpp

include/eigenpy/eigenpy.hpp

include/eigenpy/exception.hpp

include/eigenpy/fwd.hpp

include/eigenpy/geometry-conversion.hpp

include/eigenpy/geometry.hpp

include/eigenpy/map.hpp

include/eigenpy/memory.hpp

include/eigenpy/quaternion.hpp

include/eigenpy/ref.hpp

include/eigenpy/registration.hpp

include/eigenpy/stride.hpp

python/CMakeLists.txt

python/main.cpp

src/angle-axis.cpp

src/eigenpy.cpp

src/exception.cpp