* cygtls.cc (_cygtls::fixup_after_fork): Wipe out exitsock local since it

* cygtls.cc (_cygtls::fixup_after_fork): Wipe out exitsock local since it
should not be used by the child.
* select.cc (start_thread_socket): Turn off inheritance for exitsock.  Don't
add exitsock to exception mask since it should never get an exception.
(socket_cleanup): Change some debug messages for consistency.
* fhandler_socket.cc (fhandler_socket::dup): Change comment wording slightly.