Set intersection and restarting

I don't think the restarting rule is implemented correctly. In fact, I'm pretty sure it isn't. It's under `dist_ecos/admm.py`.

I modified the `dist_ecos/admm.py` module so that there is no longer an ADMM class. Instead, it's just a "solve" function. So it now works with

    from dist_ecos import ADMM
    ADMM.solve(split_func = ..., with_restart = False)

I hooked up the set intersection "socp_to_R" conversion to different covers. It still looks like general consensus with metis beats everybody, but I'd like to see what happens with restarting. We're close.