Merge pull request #406 from florent-lamiraux/devel

doc/Doxyfile.extra.in

src/algorithm/finite-differences.hxx

src/multibody/liegroup/cartesian-product.hpp

src/multibody/liegroup/operation-base.hpp

src/multibody/liegroup/operation-base.hxx

src/multibody/liegroup/special-euclidean.hpp

src/multibody/liegroup/special-orthogonal.hpp

src/multibody/liegroup/vector-space.hpp

unittest/liegroups.cpp