start parameter is passed by reference so that in case it is not in bounds
the changes made to it are reflected back to the phpBB/search.php file
PHPBB3-11179
* develop-olympus:
[ticket/10630] Use sql_like_expression() method instead of hardcoded LIKE '%x%'
[ticket/10630] Perform array_unique on authors array before creating the query
Search backends are now required to be autoloadable. The database updater to
3.1 tries to guess the class name as phpbb_search_<oldname> which works for
the default backends we ship.
PHPBB3-10323