after a user (has been) disconnected and before the node transitions to waiting
for connection (WFC) status. Usually the duration of this status is very short,
but it can be longer (e.g. for running log-out module and event) and for (new)
msg-scan pointer fix-ups.
Updated logout() to remove some cruft and add some more log/debug output.
Automatic new-scan pointer fix-ups when performing new-message scans (if the
current pointer is greater than the last message number, set it to the last
message number) and when saving message pointers.
Passing user_t* to get/putmsgptrs() instead of message number now (to better
detect Guest account).