Split vtx_graph definition (sparsegraph.h) out of defs.h so that it can be used separately without the whole world being brought in; unify the versions of matrix_ops so that we only need one for both neato and topfish.
Split vtx_graph definition (sparsegraph.h) out of defs.h so that it can be used
separately without the whole world being brought in;
unify the versions of matrix_ops so that we only need one for both
neato and topfish.

MjAbuz/graphviz,kbrock/graphviz,kbrock/graphviz,jho1965us/graphviz,jho1965us/graphviz,ellson/graphviz,tkelman/graphviz,jho1965us/graphviz,MjAbuz/graphviz,ellson/graphviz,ellson/graphviz,kbrock/graphviz,tkelman/graphviz,tkelman/graphviz,MjAbuz/graphviz,pixelglow/graphviz,kbrock/graphviz,BMJHayward/graphviz,ellson/graphviz,jho1965us/graphviz,kbrock/graphviz,MjAbuz/graphviz,jho1965us/graphviz,tkelman/graphviz,MjAbuz/graphviz,jho1965us/graphviz,pixelglow/graphviz,MjAbuz/graphviz,pixelglow/graphviz,ellson/graphviz,BMJHayward/graphviz,pixelglow/graphviz,kbrock/graphviz,pixelglow/graphviz,jho1965us/graphviz,kbrock/graphviz,kbrock/graphviz,jho1965us/graphviz,pixelglow/graphviz,tkelman/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,ellson/graphviz,jho1965us/graphviz,tkelman/graphviz,tkelman/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,pixelglow/graphviz,jho1965us/graphviz,ellson/graphviz,tkelman/graphviz,tkelman/graphviz,pixelglow/graphviz,pixelglow/graphviz,pixelglow/graphviz,kbrock/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,kbrock/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,kbrock/graphviz,ellson/graphviz,pixelglow/graphviz,ellson/graphviz,MjAbuz/graphviz,tkelman/graphviz,BMJHayward/graphviz,jho1965us/graphviz,tkelman/graphviz,MjAbuz/graphviz,ellson/graphviz,ellson/graphviz