Fallback to `SET NAMES ...` if the PHP version doesn't include mysql_set_charset()

PHP versions 5.2.0, 5.2.1 and 5.2.2 do not include mysql_set_charset. To set PHP 5.2 as a minimum requirement we need to fallback to `SET NAMES...` if we can't use mysql_set_charset().
Minor, consistent use of periods
Remove "seconds" suffix from language string