Description:
------------
A database connection to SQLite3 can not be closed if I create a prepared statement without executing it.

Of course, I have already closed that statement explicitly before closing the database connection handler.

I had this warning: Unable to close due to unfinalised statements. It means that an invocation to close() on a statement handler does not work.

Reproduce code:
---------------
<?php

// By default, open uses SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE.
$db   = new SQLite3('./test.db');

$sql  = 'SELECT 1';

$stmt = $db->prepare($sql);

// Commenting out the line intentionally
// $rs = $stmt->execute();

if (true === $stmt->close())
{
    echo 'Statement is already closed but in this case it is not. ';
}

if (false === $db->close())
{
    echo 'But database connection can not be closed due to an error: '.$db->lastErrorMsg();
}
?>

Expected result:
----------------
Database connection should be closed as usual

Actual result:
--------------
The error message:

Statement is already closed but in this case it is not.
Warning: SQLite3::close() [sqlite3.close]: Unable to close database: 5, Unable to close due to unfinalised statements in D:\wvbsrc\repos\pone\trunk\tests\Plugin\test2_sqlite3.php on line 18
But database connection can not be closed due to an error: Unable to close due to unfinalised statements