[ticket/11859] Make avatar drivers return template filename

The service name might not follow the expected naming scheme which would
cause abnormally long filenames and confusion for authors that might add
more avatar drivers.

PHPBB3-11859
[ticket/11859] Add missing get_template_name method to test drivers

PHPBB3-11859
[ticket/12054] Update index_body_linklist_before/after template events

PHPBB3-12054
[ticket/12060] Add template event acp_bbcodes_edit_form_append

PHPBB3-12060
[ticket/12060] Add template event acp_bbcodes_actions_prepend/append

PHPBB3-12060
[ticket/12060] Add template events posting_editor_buttons_before/after

PHPBB3-12060
[ticket/12060] Wrap subsilver2 posting buttons in div with id tags

Wrap the posting buttons in div tags with id attributes to allow needed
ability to process them with CSS, for example, to hide them.

PHPBB3-12060
[ticket/12060] Add acp event core.acp_bbcodes_edit_add

Modify bbcode template before we display the add/edit form

PHPBB3-12060
[ticket/12060] Add acp event core.acp_bbcodes_modify_create

Modify bbcode data before modify/create

PHPBB3-12060
[ticket/12060] Add acp event core.acp_bbcodes_display_form

Modify bbcode template data before we display the form

PHPBB3-12060
[ticket/12060] Add acp event core.acp_bbcodes_display_bbcodes

Modify display of bbcodes in the form

PHPBB3-12060
[ticket/12060] Add $phpbb_dispatcher to acp_bbcodes.php for events

PHPBB3-12060
[ticket/12060] Add event core.display_custom_bbcodes_modify_sql

Modify the SQL statement retrieving the custom bbcodes

PHPBB3-12060
[ticket/12060] Add event core.modify_bbcode_init

Use this event to modify the bbcode data for later parsing

PHPBB3-12060
[ticket/12060] Add event core.modify_text_for_format_display_after

Use this event to modify the text after it is parsed

PHPBB3-12060
[ticket/12060] Fix a core typo in display_custom_bbcodes doc block

PHPBB3-12060
[ticket/12060] Use actions class for BBCodes list in ACP

PHPBB3-12060
[ticket/12060] Add bbcode tokens array to core.acp_bbcodes_edit_add

PHPBB3-12060
[ticket/12060] Fix typo in core.acp_bbcodes_edit_add doc block

PHPBB3-12060
[ticket/12063] Remove obsolete valign attributes from tr tags

PHPBB3-12063