Removes the need to keep a second transaction around and marking it as
`noleak`, just to make sure that dependencies are not free'd along
with the original tx.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
We create a temporary tx which is a child of the real tx, for simplicity of
marshalling. That's OK.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>