[ticket/11697] author_search() used incorrect parameter

The author_search() function in fulltext_mysql.php had an argument
$m_approve_fid_ary parameter but it was changed in the Docblock
and code to $post_visibility. This change renames that argument
according to the docblock, the code and to mirror the other classes.

PHPBB3-11697
[ticket/9550] Add multiple template events required for the karma extension

The karma extension needs some new template events to display members' karma
scores in various places. This commit adds them.

Also see http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=44379

PHPBB3-9550