Description:
------------
PDO_OCI doesn't yet allow fetching ref cursors with oracle (or any other database). 

This patch adds support for fetching reference cursors on pdo_oci on both SELECT's as well CALL's to stored procedures (see the example below).


Test script:
---------------
$dbh = new PDO('oci:dbname=//localhost/XE', 'user', 'pass');
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);

$sql = "select cursor(select table_name, owner from all_tables where rownum <= 1) as cursor from dual";
$sth = $dbh->prepare($sql);
$sth->execute();

$row = $sth->fetch(PDO::FETCH_ASSOC);
var_dump($row);
if (is_a($row['CURSOR'],'PDOStatement')) {
    $sthc = $row['CURSOR'];
    while ($rr = $sthc->fetch(PDO::FETCH_ASSOC)) {
      var_dump($rr);
    }
 }
$sql = "begin OPEN :c FOR 'SELECT table_name FROM all_TABLES WHERE ROWNUM <= 1'; END;";

$sthc = '';
$sth = $dbh->prepare($sql);
$sth->bindParam(":c", $sthc, PDO::PARAM_STMT|PDO::PARAM_INPUT_OUTPUT);

$sth->execute();
if ($sthc && is_a($sthc,'PDOStatement'))
  while ($rr = $sthc->fetch(PDO::FETCH_ASSOC)) {
    var_dump($rr);
  }


Expected result:
----------------
array(1) {
  ["CURSOR"]=>
  object(PDOStatement)#3 (1) {
    ["queryString"]=>
    NULL
  }
}
array(2) {
  ["TABLE_NAME"]=>
  string(5) "ICOL$"
  ["OWNER"]=>
  string(3) "SYS"
}
array(1) {
  ["TABLE_NAME"]=>
  string(5) "ICOL$"
}


Actual result:
--------------
PHP Warning:  PDOStatement::fetch(): SQLSTATE[HY000]: General error: 932 OCIStmtFetch: ORA-00932: inconsistent datatypes: expected CHAR got DTYCWD


Warning: PDOStatement::fetch(): SQLSTATE[HY000]: General error: 932 OCIStmtFetch: ORA-00932: inconsistent datatypes: expected CHAR got DTYCWD
bool(false)
PHP Warning:  PDOStatement::execute(): SQLSTATE[HY000]: General error: 1008 OCIStmtExecute: ORA-01008: not all variables bound

Warning: PDOStatement::execute(): SQLSTATE[HY000]: General error: 1008 OCIStmtExecute: ORA-01008: not all variables bound