Add latex-feynmf 1.08.19961202,

feynmf is a combined LaTeX/Metafont package for easy drawing of
professional quality Feynman diagrams. feynmf lays out most
diagrams satisfactorily from the structure of the graph without
any need for manual intervention. Nevertheless all the power
of Metafont is available for more obscure cases.

PR: ports/61921
Submitted by: hrs@FreeBSD.org