Connector::unionize

static function unionize($sqls)
{
	if(!is_array($sqls))
		return $sqls;

	if(count($sqls) == 1)
		return array_shift($sqls);

	//foreach($sqls as &$sql)
	//	$sql = '('.$sql.')';

	unset($sql);

	return implode(' union ', $sqls);
}