XML messages may get interleaved if longer than PIPE_BUF

[michaelforney]

Since all the subdaemons communicate with sj using the same FIFO, I think the XML messages may be interleaved if any are larger than PIPE_BUF (POSIX says this could be as low as 512).

Maybe instead of a FIFO, sj should use a UNIX domain socket so that each subdaemon gets it's own FD?