`openchannel_signed` and `openchannel_update` which allow a user to continue a openchannel or kick off the completion of a openchannel. `openchannel_update` should be called until it returns with `commitments_secured`.
Switch on name of subd(aemon) as to whether to call dualopend or openingd for memleak results
We're going to reuse all this code for dualopend, which is coming soon.
