Check if master and slave are in the same state before running the log.

Be a bit less repetitive with the logger
Close our fds when hitting the write child, always recalculate state
after applying logs.

Force readonly mode after I/O errors on the disk store.
Do not reset dn when rewriting disk data.
mention cyon-cmd
Only set modified if we're not in readonly while replaying a log
Less noise about state changes if they aren't.

Revert last change as well, god i need tests.