[ticket/12961] Add link in anti-spam ACP page to titania

PHPBB3-12961
[ticket/12961] Change url to https://www.phpbb.com/go/anti-spam/

PHPBB3-12961
[ticket/12961] Change url to anti-spam-ext

As per IRC suggestion

PHPBB3-12961
[ticket/12961] Refactor lang entry

PHPBB3-12961
[ticket/12961] Move link to language file

PHPBB3-12961
[ticket/12961] Add additional link to the KB

PHPBB3-12961
[ticket/12961] Remove target="_blank" and switch to <strong>

PHPBB3-12961
[ticket/12961] Fix missing phpBB.com

Don't know how that happened. Weird

PHPBB3-12961
[ticket/12961] Shorten ext-db link text

PHPBB3-12961
[ticket/13034] Fix the route generated for the frontend not in the phpbb root

PHPBB3-13034
[ticket/13022] Condition Return to advanced search link

PHPBB3-13022
[ticket/13022] Remove ternary condition

PHPBB3-13022
[ticket/13022] Language adjustments

PHPBB3-13022
[ticket/12963] Fix the list of migrations in database_update.php

Without this patch the finder grab all the class available in the ext
folder and not only the migrations. This change is backported for the one
done before to the cli tool db:migrate. (see the commit
3420f8f3201ac337434f73ee00bda6df7b378212)

PHPBB3-12963
[ticket/12963] Don't use static var in \extension\base\get_migration_file_list

The static var was global to all instance of \phpbb\base and so if two
different instances (for two different extensions) were created by the
same script they shared the same migrations list.

PHPBB3-12963
[ticket/12963] Load extensions migrations from /migration

PHPBB3-12963
[ticket/13061] Replace the service event.subscriber_loader by a compiler pass

PHPBB3-13061
[ticket/13062] Add viewforum.php core event to modify topic ids sql query

Event request: http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=45383

PHPBB3-13062
[ticket/13064] Validate the migrations provided to migrator::set_migrations()

PHPBB3-13064
[ticket/13066] Add search results core event to modify search title

PHPBB3-13066