This requires a small changes to a few tests, but means that
deterministic addresses will always be imported (unless setup_nodes
behaviour is explicitly overridden).
The blockmaxsize option was marked as deprecated in V0.15.1, and code
was added to convert provided blockmaxsize into blockmaxweight. However,
this code was incorrectly implemented, and blockmaxsize was silently
ignored.
No users have complained about blockmaxsize being ignored, so just
remove it in V0.17.
John Newbery