objective function unification

[rb004f]

Consider unifying the objectives (and problem formulations) min_ne, min_opf, and min_ne_opf as a single function. min_ne is min_ne_opf without opf and min_opf is min_ne_opf without ne. With 0 cost provided as inputs, min_ne_opf could be used to model all three examples. Is there value in modeling these three problems independently?

[tasseff]

I think this makes a lot of sense, and I would prefer to collapse these problem specifications into one. Then we would eventually have only three problem specifications: gf, ne_opf, and mld.