Save & Load MUL

[WEKarnesky]

To extend the usefulness of Battle-Force-Balancer, we should save and load MML's MUL files (collections of mechs) so we can create teams, save them, then load in MM. Or Take teams from MekHQ and then load in and print in BFB.

I think this requires that #35 be done first, but research is needed.