Description:
------------
The SQLite3Result::columnType() method returns SQLITE3_NULL (5) when column_number exceeds the column count.  It seems more appropriate for it to return FALSE.


Test script:
---------------
$db = new SQLite3(':memory:');

$db->exec('CREATE TABLE test (whatever INTEGER)');
$db->exec('INSERT INTO test (whatever) VALUES (1)');

$result = $db->query('SELECT * FROM test');
while ($row = $result->fetchArray(SQLITE3_NUM)) {
    var_dump($result->columnType(0));  // int(1)  [SQLITE3_INTEGER]

    // Seems returning false is more appropriate.
    var_dump($result->columnType(3));  // int(5)  [SQLITE3_NULL]
}

$result->finalize();
$db->close();

echo "Done\n";


Expected result:
----------------
int(1)
bool(false)
Done


Actual result:
--------------
int(1)
int(5)
Done