moved files around to fit new structure

merged black scholes tests
removed files with duplicated functionality
Yeah I haven't figured this out at all. I was just trying something here. What I don't want is duplicated code for valuing Futures/Swaps/FFAs/TAS which are all basically the same thing with some minor variation. But I'm not sure what that should look like. I thought a SwapLikeValuer would be used for all of them. Or something like that.

So you think just a single Valuer class to link the valuation code to the contract definition code? I guess that matches on type and can pass valuation onto more specific classes?