To avoid everything pulling in HTLCs stuff to the opening daemon, we
split the channel and commit_tx routines into initial_channel and
initial_commit_tx (no HTLC support) and move full HTLC supporting versions
into channeld.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Added channel announcement serialization and parsing, as well as the
entrypoints for the IRC peer discovery. Announcements are signed by the
sending endpoint and signatures are verified before adding the channels
to the local view of the topology. We do not yet verify the existence of
the anchor transaction.