fully qualifying stan::gm::sample. This fixes the issue with g++ 4.4
fully qualifying stan::gm::sample. This fixes the issue with g++ 4.4

stan-dev/math,stan-dev/stan,stan-dev/math,stan-dev/math,stan-dev/stan,stan-dev/math,stan-dev/stan,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/stan,stan-dev/math,stan-dev/stan