Created sbbs_t::signal_sub_sem() method to handle creation of global
echomail_sem (for FTN sub-boards) and the sub-boards post_sem (if confiugred).

set_socket_options() ignores TCP options on non-TCP sockets.

the wrapper in xpsem.c however did not necessarily... now using a compliant
sem_timedwait() in xpsem.

necessarily set the global errno (duh)

registry keys.

ctrl_dir otherwise. Each node's spy socket has a unix filename.
This is done since it is expected the temp directory will be on the local
file system (which will allow special files to be created).

log spy socket error (just break loop).

block size average).

block size average).
Removed unused "reserved" members (we don't mix DLLs from diff versions).

unused (passing NULL).

[untested]

something like this.

max_inactivity (seconds) - reversing Deuce's last change.