daemon/barebone: add |SERVER_USE_PTHREADS| option to support threading.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6081 63ad8ddf-47c3-0310-b6dd-a9e9d9715204
boardd: multi-thread.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6082 63ad8ddf-47c3-0310-b6dd-a9e9d9715204