[ticket/12001] Ensure that form data is sent to server in AJAX requests.

PHPBB3-12001
[ticket/12005] Remove PM popup setting from user preferences
PHPBB3-12005
[ticket/12005] Remove PM popup from converter
PHPBB3-12005
[ticket/12005] Remove PM popup UCP module
PHPBB3-12005
[ticket/12005] Remove PM popup
PHPBB3-12005
[ticket/12005] Remove language vars used by PM popup
PHPBB3-12005
[ticket/12005] Delete templates files
PHPBB3-12005
[ticket/12005] Remove PM popup module from DB
PHPBB3-12005
[ticket/12010] Make the navbar icons clickable.

PHPBB3-12010
[ticket/12015] Add more parameters to core.viewtopic_get_post_data

PHPBB3-12015
[ticket/12015] Add attachments to core.viewtopic_modify_post_row

PHPBB3-12015
[ticket/12015] Add an event after the post has been assigned to the template

PHPBB3-12015
[ticket/12015] Add post counting information to event

PHPBB3-12015
[ticket/12015] Add @change to events that got changed

PHPBB3-12015
[ticket/12015] Add some parameters to viewonline events

PHPBB3-12015
Merge pull request #1860 from prototech/ticket/12010

[ticket/12010] Make the navbar icons clickable.
Merge pull request #1856 from prototech/ticket/12001

[ticket/12001] Ensure that form data is sent to server in AJAX requests.
Merge pull request #1854 from Pico88/ticket/12005

[ticket/12005] Remove code responsible for PM popup completely
[ticket/12015] Fix english grammar

PHPBB3-12015
[ticket/12028] Replace L_COLON with literal colon

Replace L_COLON with literal colon in JavaScript context.

[ci skip]

PHPBB3-12028