Rewrote error & log functions to be more general, use longjmp to get out of

trouble and into predictable cleanup functions (one for each of serve,
client & control contexts).  We use 'fatal' to mean 'kill the thread' and
'error' to mean 'don't kill the thread', assuming some recovery action,
except I don't use error anywhere yet.

src/self_pipe.c

@@ -35,8 +35,7 @@ void self_pipe_server_error( int err, char *msg )
 
 	strerror_r( err, errbuf, 1024 );
 
-	debug(msg);
-	SERVER_ERROR( "%s\t%s", msg, errbuf );
+	fatal( "%s\t%s", msg, errbuf );
 }
 
 /**