[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/13034] Fix the route generated for the frontend not in the phpbb root

PHPBB3-13034
[ticket/13034] Fix unit tests

PHPBB3-13034
[ticket/12983] Correctly validate sorting options in the UCP

PHPBB3-12983
[ticket/12983] Add functional test for ucp pref module

PHPBB3-12983
[ticket/13046] Call phpbb_load_extensions_autoloaders() in $download/file.php

PHPBB3-13046
[ticket/13047] Add $post_list array to core.viewtopic_modify_page_title event

PHPBB3-13047
[ticket/13048] Only update session_page if request is not ajax

PHPBB3-13048
[ticket/12983] Do not test invalid values until Symfony 2.4

PHPBB3-12983
Merge pull request #2925 from nickvergessen/ticket/12983

Ticket/12983 UCP preferences, Display posts ordering by: input is not properly validated
Merge pull request #2928 from Nicofuma/ticket/13046

[ticket/13046] Call phpbb_load_extensions_autoloaders() in $download/file.php

* Nicofuma/ticket/13046:
  [ticket/13046] Call phpbb_load_extensions_autoloaders() in $download/file.php
Merge pull request #2929 from rxu/ticket/13047

[ticket/13047] Add $post_list array to core.viewtopic_modify_page_title event

* rxu/ticket/13047:
  [ticket/13047] Add $post_list array to core.viewtopic_modify_page_title event
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