fixing fallthrouh for gcc and making it homogeneous
gcc 7.4.0 on ubuntu 18.04 complains about BOOST_FALLTHROUGH;
so I replaced it with /* Falls through. */
which was already used in other parts of the code.
gcc 7.4.0 on ubuntu 18.04 complains about BOOST_FALLTHROUGH;
so I replaced it with /* Falls through. */
which was already used in other parts of the code.