This finished the previous patch by simply copying funding_next to funding
when we want to apply changes.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes it easier to test for validity, though we still double-check
that a change doesn't overlap previous changes.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We simply record how many fee changes there are, rather than supporting
a particular level.
Fees are tricky: it's a noop to apply them when incoming, but we apply them
when they've been acked. Unlike HTLC modifications, which are symmetric,
fee updates only apply when returning to the originating node.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
