( resource id [, array & result])
yaz_scan_result() returns terms and associated
information as received from the target in the last performed
This function returns an array (0..n-1) where n is the number
of terms returned. Each value is a pair where the first item is the
term, and the second item is the result-count.
If the optional parameter result is given it will be
modified to hold additional information taken from the Scan Response:
number (number of entries returned),
position (position of term),
status (Scan Status).