`struct log` becomes `struct logger`, and the member which points to the
`struct log_book` becomes `->log_book` not `->lr`.

Also, we don't need to keep the log_book in struct plugin, since it has
access to ld's log_book.

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

Rather than exposing the filtering internals.

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

This is where it's set, not some random logger.

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

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

Rather than initializating the "print_level" field on first use, we can
do it in logging_options_parsed(), now we have a linked list of them.

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

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

Fixes: ElementsProject#5392
Changelog-Added: config: `log-level` can be specified on a per-logfile basis.

Without this, only per-peer daemons were filtered correctly.  For generic
daemons, we need to filter with the actual nodeid they use (if any).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Fixed: config: `log-level` filters now apply correctly to messages from `connectd`.