> Also change

> arrayfuncs.cholesky_delete(L[:n_active, :n_active], idx)

> to

> [arrayfuncs.cholesky_delete(L[:n_active, :n_active], ii) for ii in idx]

> to be completely rigurous about what idx is

@cli248: could you post a comment on this PR once you have done the
change, so that I don't miss it, and I can merge.

Thanks a lot