Call for potential ports maintainers

[Stephen Montgomery-Smith]

I guess I could take these ports:

/usr/ports/cad/gmsh
/usr/ports/cad/netgen
/usr/ports/graphics/opendx
/usr/ports/graphics/plotutils
/usr/ports/math/GiNaC
/usr/ports/math/arpack
/usr/ports/math/bamg
/usr/ports/math/qhull
/usr/ports/science/cdf
/usr/ports/science/getdp