protocol: fix horribly thinko, keep own secrets.

I had each side using the other side's hash secret.  That's a very
dumb idea, since it means you can steal from a unilateral close!

A's secret applies to A's commit transaction: it needs the
secret and B's final signature to steal funds, and that should
never happen (since A doesn't have the B's final signature, and
once A has given B the secret, they never broadcast the commit tx).

This makes the update a 4 step dance, since you need the new
revocation hash to make the other side's TX to sign.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

create-commit-spend-tx.c

@@ -105,7 +105,7 @@ int main(int argc, char *argv[])
 
 	/* Now get signature, to set up input script. */
 	if (!sign_tx_input(tx, tx, 0, redeemscript, tal_count(redeemscript),
-			   privkey, &sig.sig))
+			   privkey, &pubkey1, &sig.sig))
 		errx(1, "Could not sign tx");
 	sig.stype = SIGHASH_ALL;
 	tx->input[0].script = scriptsig_p2sh_single_sig(tx, redeemscript,