[ticket/12160] Add function to check if phpBB is installed.

PHPBB3-12160
[ticket/12160] Check if phpBB is installed before creating phpBB container.

PHPBB3-12160
[ticket/12160] Move phpbb_check_installation_exists() to functions_install.php

PHPBB3-12160
[ticket/12160] Use phpbb_check_installation_exists() in the other modules.

PHPBB3-12160
[ticket/11239] Including username before Overview title

Adding username to the page title to avoid confusion while managing
multiple users in ACP

PHPBB3-11239
[ticket/11071] Add fallback if requested style don't exist

PHPBB3-11071
[ticket/8309] Renaming "Last visit" to "Last activity"

PHPBB3-8309
[ticket/8309] Rename $last_visit to $last_activity

PHPBB3-8309
[ticket/11169] Move module 'prune users' to users category

PHPBB3-11169
[ticket/12274] Load correct T_TEMPLATE_PATH during update

PHPBB3-12274
[ticket/8309] Moving key to get keys in alphabetical order

PHPBB3-8309
[ticket/11239] Removing hard-coded, language specific possessive

PHPBB3-11239
[ticket/12274] Fix broke/missing jQuery asset paths in update script

PHPBB3-12274
[ticket/12274] Add core.js to the install footer

Required so phpbb var is defined, as it is used in admin.js.

PHPBB3-12274
[ticket/10590] Remove confirmation page after posting

PHPBB3-10590
Merge pull request #2136 from Elsensee/ticket/11071

[ticket/11071] Add fallback if requested style don't exist
Merge remote-tracking branch 'vsephpbb/ticket/12274' into develop

* vsephpbb/ticket/12274:
  [ticket/12274] Add core.js to the install footer
  [ticket/12274] Fix broke/missing jQuery asset paths in update script
  [ticket/12274] Load correct T_TEMPLATE_PATH during update
Merge branch 'ticket/11239' of github.com:geetakshi/phpbb into develop

# By geetakshi
# Via geetakshi
* 'ticket/11239' of github.com:geetakshi/phpbb:
  [ticket/11239] Removing hard-coded, language specific possessive
  [ticket/11239] Including username before Overview title
[ticket/7580] Add test for IF {VAR} is defined in templates

http://tracker.phpbb.com/browse/PHPBB3-7580
This test demonstrates that is possible to test if a
variable exists and then use it if it does, similar to
using isset(), but in template/twig syntax.
<!— IF {VAR} is defined —>{VAR}<!— ENDIF —>

PHPBB3-7580
[ticket/12269] Delete folder mods in language

Deleted mods folder in phpbb/language/en/.

PHPBB3-12269