[ticket/13133] Allow @vendor_name for includecss

PHPBB3-13133
[ticket/13133] Add unit tests

PHPBB3-13133
[ticket/11863] Grey out unavailable activation methods when emails disabled

Further fall back to USER_ACTIVATION_DISABLE when emails are disabled
but evaluate it at runtime.

PHPBB3-11863
[ticket/11863] Display warning to user because of activation method

PHPBB3-11863
[ticket/11863] Add functional test

PHPBB3-11863
[ticket/13100] Display only confirmation buttons when deleting shadow topic

PHPBB3-13100
[ticket/13197] Also delete group avatar from users that have it set

PHPBB3-13197
[ticket/13197] Test that user's group avatar is deleted by group avatar delete

PHPBB3-13197
[ticket/13204] Tell user that password was incorrect when exceeding attempts

At the end of the login method, the captcha was entered correctly and only
the password was incorrect. Therefore, just tell the user that the password
was incorrect. He will see that he still needs to enter a captcha.

PHPBB3-13204
[ticket/13100] Remove pointless variable

PHPBB3-13100
[ticket/13284] Fix request name so users can cc themselves

PHPBB3-13284
[ticket/13284] Set message body in topic form too, so it will be sent

PHPBB3-13284
[ticket/13133] Rename $ok variable

PHPBB3-13133
[ticket/13220] Add template events to memberlist_search.html

PHPBB3-13220
[ticket/13309] Add event acp_email_options_after

PHPBB3-13309
[ticket/13310] Always use sql_build_query in acp_email.php

PHPBB3-13310
[ticket/13197] Correctly format sql query

PHPBB3-13197
[ticket/13197] Fix tabbing

PHPBB3-13197
[ticket/13297] Add unicode modifier to url/email regular expression patterns.

PHPBB3-13297
[ticket/13310] Add event core.acp_email_modify_sql

PHPBB3-13310