Partial rewrite of fw_sync_with_auth #168
This code needs a lot of testing and probably has remaining bugs but it attempts to avoid being affected by client_list changes in any way.
The trick is that the entire client list gets duplicated and the mutex is dropped and then the copy is processed.
Mutex are re-acquired and the client refound (by mac and ip) before being changed. Explicit checks exist for client that no longer exist.
This aims at resolving #84