Fixed MANTIS-4530 (Catalogue rating sort broken)

  - [tt]force_memory_sort__<catalogue-name>[/tt] -- set this to '1' to force an in-memory sort on a particular catalogue (this is slower, but it will sort more accurately by resolving language string fallback and Comcode fully before sorting)

  - [tt]search_do_days_fallback[/tt] -- set this to '0' if you don't want to re-search without a recency filter if no results were found

  - [tt]sitemap_orphans_to_pages[/tt] -- set this to '0' if you don't want orphaned pages to be put under the default Pages page grouping of the Sitemap 

  - [tt]time_sensitive_rankings__<catalogue_name>[/tt] -- set this to a number for catalogue rating sorting to only consider this number of records. This is useful for a upvote/downvote system that is responsive to change in voting pattern.

 - Performance tuning (positive) [not official options as will break normal expectations of how the system will behave / complicate things]

  - [tt]slow_php_dns[/tt] -- set this to '1' if the server has very slow DNS resolution on the web server's main network interface, and therefore to do DNS resolution via the command line instead

  - [tt]lots_of_data_in_*[/tt] -- set this to '1', with '*' replaced with a database table name, if you want the Selectcode mechanism to work with recursive DB lookups rather than one huge flat lookup

    // Special case for ratings

    $matches = ($filter_key == 'compound_rating') ? array('', $info['feedback_type_code']) : array();

    if (($filter_key == 'compound_rating') || (preg_match('#^compound_rating\_\_(.+)#', $filter_key, $matches) != 0)) {

        if ($filter_key == 'compound_rating') {

            $matches[1] .= '__' . $catalogue_name;

        }

        $clause = '(SELECT SUM(rating-1) FROM ' . $db->get_table_prefix() . 'rating rat WHERE ' . db_string_equal_to('rat.rating_for_type', $matches[1]) . ' AND rat.rating_for_id=' . db_cast($table_join_code . '.' . $first_id_field, 'CHAR') . ')';

        $extra_select[$filter_key] = ', ' . $clause . ' AS compound_rating_' . fix_id($matches[1]);

        return array($clause, '', $filter_val);

    }

    $matches = ($filter_key == 'average_rating') ? array('', $info['feedback_type_code']) : array();

    if (($filter_key == 'average_rating') || (preg_match('#^average_rating\_\_(.+)#', $filter_key, $matches) != 0)) {

        if ($filter_key == 'average_rating') {

            $matches[1] .= '__' . $catalogue_name;

        $table_and_where = $db->get_table_prefix() . 'rating rat WHERE ' . db_string_equal_to('rat.rating_for_type', $matches[1]) . ' AND rat.rating_for_id=' . db_cast($table_join_code . '.' . $first_id_field, 'CHAR');

        if ($catalogue_name !== null) {

            $time_sensitivity = get_value('time_sensitive_rankings__' . $catalogue_name, '');

            if ($time_sensitivity != '') {

                $table_and_where = '(SELECT * FROM ' . $table_and_where . ' LIMIT ' . strval(intval($time_sensitivity)) . ') ' . uniqid(''); // TODO: MySQL-only, fix in v11

            }

        }

        $clause = '(SELECT AVG(' . db_cast('rating' , 'FLOAT') . ')/2 FROM ' . $db->get_table_prefix() . 'rating rat WHERE ' . db_string_equal_to('rat.rating_for_type', $matches[1]) . ' AND rat.rating_for_id=' . db_cast($table_join_code . '.' . $first_id_field, 'CHAR') . ')';

        $clause = '(SELECT AVG(' . db_cast('rating' , 'FLOAT') . ')/2 FROM ' . $table_and_where . ')';

        $clause = db_function('COALESCE', array($clause, '2.5'));

        $extra_select[$filter_key] = ', ' . $clause . ' AS average_rating_' . fix_id($matches[1]);

        return array($clause, '', $filter_val);

    }

    // Random

    $matches = ($filter_key == 'fixed_random') ? array('', $info['feedback_type_code']) : array();

    if (($filter_key == 'fixed_random') || (preg_match('#^fixed_random\_\_(.+)#', $filter_key, $matches) != 0)) {

        if ($filter_key == 'fixed_random') {

            $matches[1] .= '__' . $catalogue_name;

        }

        $clause = db_cast('r.' . $first_id_field, 'INT');

        $clause = '(' . db_function('MOD', array($clause, date('d'))) . ')';

        $extra_select[$filter_key] = ', ' . $clause . ' AS fixed_random_' . fix_id($matches[1]);