+/**
+ * Queues a new asynchronous job represented by 'callback' and 'arg[123]'
+ * for the 'group' and the 'timeout'.
+ * Jobs are queued FIFO and are possibly executed in parallel
+ * concurrently except for job of the same group that are
+ * executed sequentially in FIFO order.
+ * @param group The group of the job or NULL when no group.
+ * @param timeout The maximum execution time in seconds of the job
+ * or 0 for unlimited time.
+ * @param callback The function to execute for achieving the job.
+ * Its first parameter is either 0 on normal flow
+ * or the signal number that broke the normal flow.
+ * The remaining parameters are the parameters 'arg[123]'
+ * given here.
+ * @param arg1 The second argument for 'callback'
+ * @param arg2 The third argument for 'callback'
+ * @param arg3 The forth argument for 'callback'
+ * @return 0 in case of success or -1 in case of error
+ */