[ticket/12982] Refactoring: made most JS nice.

PHPBB3-12982
[ticket/12982] Refactoring: made JS in adm nice

PHPBB3-12982
[ticket/12982] Refactoring: Cleaned up phpbb.search

PHPBB3-12982
[ticket/12982] Refactoring: Cleaned up forum_fn.js

PHPBB3-12982
[ticket/12982] Refactoring: Cleaned up crazy insert users stuff

PHPBB3-12982
[ticket/13005] Add event to display_forums() to modify category template data

While there're events to modify/add FORUM_POST/FORUM_LINK template data,
such an event is missing for FORUM_CAT forum type.

PHPBB3-13005
[ticket/13006] Add variables to the 'core.modify_quickmod_actions' event

Add $quickmod and $action variables
for the 'core.modify_quickmod_actions' event trigerring
to avoid of using global operator in corresponding extensions.

PHPBB3-13006
[ticket/13048] Only update session_page if request is not ajax

PHPBB3-13048
Merge pull request #2930 from Senky/ticket/13048

[ticket/13048] AJAX requests are being stored to session_page

* Senky/ticket/13048:
  [ticket/13048] Only update session_page if request is not ajax
[ticket/13050] Allow topic/forum subscription when email/jabber is off

Currently, there's impossible to subscribe topic/forum if emails and/or jabber
is disabled. This seems to be a 3.0 leftover since 3.1 introduces new
notification system which handles this case and offers email/jabber-free
board notifications.

PHPBB3-13050
[ticket/13026] Add template vars array to core.viewonline_overwrite_location

Add template vars array to core.viewonline_overwrite_location event
to allow modifying/adding template vars for every user row.

PHPBB3-13026
[ticket/13020] Add forum_data variable to core.viewforum_get_topic_data event

PHPBB3-13020
[ticket/13035] Remove empty meta tags

PHPBB3-13035
Merge pull request #2933 from bantu/ticket/13035

[ticket/13035] Remove empty meta tags

* bantu/ticket/13035:
  [ticket/13035] Remove empty meta tags
Merge pull request #2911 from rxu/ticket/13020

[ticket/13020] Add variables to core.viewforum_get_topic_data event
Merge pull request #2915 from rxu/ticket/13026

[ticket/13026] Add template vars array to core.viewonline_overwrite_location
[ticket/13038] Add link to number of posts of user in viewtopic

PHPBB3-13038
Merge pull request #2931 from rxu/ticket/13050

[ticket/13050] Allow topic/forum subscription when email/jabber is off

* rxu/ticket/13050:
  [ticket/13050] Allow topic/forum subscription when email/jabber is off
Merge pull request #2926 from Senky/ticket/13038

[ticket/13038] Link user post tally to their posts

* Senky/ticket/13038:
  [ticket/13038] Add link to number of posts of user in viewtopic
[ticket/13051] Fix viewonline event, remove template data

PHPBB3-13051