We alternated between using a sha256 and using a privkey, but there are
numerous places where we have a random 32 bytes which are neither.
This fixes many of them (plus, struct privkey is now defined in terms of
struct secret).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This lets us link HTLCs from one peer to another; but for the moment it
simply means we can adjust balance when an HTLC is fulfilled.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a peer dies, and then we get a reply, that can cause access after free.
The usual way to handle this is to make the request a child of the peer,
but in fact we still want to catch (and disard) it, so it's a little
more complex internally.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
