( [array options])
This function carries out networked (blocked) activity for
outstanding requests which have been prepared by the functions
yaz_scan() and yaz_itemorder().
yaz_wait() returns when all targets have either
completed all requests or aborted (in case of errors).
If the options array is given that holds
options that change the behaviour of yaz_wait().
Sets timeout in seconds. If a target has not responded within
the timeout it is considered dead and yaz_wait()
returns. The default value for timeout is 15 seconds.