[ticket/12078] Check for f_delete when a user attempts to permanently delete

PHPBB3-12078
[ticket/12093] Check that document.selection is supported.

PHPBB3-12093
[ticket/12132] Add viewtopic_print_head_append event to subsilver2

PHPBB3-12132
[ticket/12132] Add the event to events.md doc

PHPBB3-12132
[ticket/12134] Add ucp_pm_viewmessage_print_head_append event to subsilver2

PHPBB3-12134
[ticket/12136] Use new pagination class in generate_smilies().

PHPBB3-12136
[ticket/12153] Assign PAGE_NUMBER in pagination.generate_template_pagination()

PHPBB3-12153
[ticket/12153] Remove vars already assigned in generate_template_pagination().

PHPBB3-12153
[ticket/12153] Remove redundant calls to pagination.on_page().

PHPBB3-12153
[ticket/12153] Adjust pagination tests.

PHPBB3-12153
[ticket/12158] The pagination start value should be 0 when there are no items.

PHPBB3-12158
[ticket/12158] Add test data for 0 items to validate_start() test.

PHPBB3-12158
[ticket/12167] Allow users to change style via style parameter by default

This change will enable users that don't have the a_styles permission to
preview styles using the style parameter. Using this, they will be able to
use extensions that are or incorporate stylechangers.

PHPBB3-12167
[ticket/12171] Check topic visibility before allowing to download attachments

PHPBB3-12171
[ticket/12171] Split post and pm download links

PHPBB3-12171
PHPBB3-12172
[ticket/12171] Check post visibility before being able to download attachments

PHPBB3-12171
[ticket/12171] Send correct status 403 when forbidden and 404 when not found

PHPBB3-12171
[ticket/12171] Add functionality to upload attachments to submit_post() method

PHPBB3-12171
[ticket/12171] Add functional tests for downloading attachments

PHPBB3-12171
[ticket/12183] Update user_newpasswd column to length of 255 in schema files

PHPBB3-12183