[MEDIUM] the stats dump FSM was buggy and looped on dispatch instances.

[MEDIUM] the stats dump FSM was buggy and looped on dispatch instances.

It has been rewritten and now supports an initialization state. It now also
prevents from dumping stopped(disabled) listeners and it is possible to
specify a scope with a list of proxies that are allowed to be dumped from
the one being configured ('.' meaning "this one"). The 'stats' entry can
be configured from the 'defaults' instance and it is correctly flushed
from proxies which redefine it.