add table and column quote support, see #94

[shellvon]

支持表名/字段名的转义,防止SQL错误:

$miner = new Miner();
$sql = (string)$miner->select('*')
    ->from('shows', 'group')
    ->innerJoin('episodes', 'show_id')
    ->where('shows.network_id', 12)
    ->orderBy('episodes.aired_on', Miner::ORDER_BY_DESC)
    ->limit(20)->getStatement(false);
echo $sql;
// SELECT * FROM `shows` AS `group` INNER JOIN `episodes` ON `shows`.`show_id` = `episodes`.`show_id` WHERE `shows`.`network_id` = '12' ORDER BY `episodes`.`aired_on` DESC LIMIT 20