[ticket/9758] Adds global template variable CURRENT_USER_AVATAR

PHPBB3-9758
[ticket/9758] Changes class name of new "span" in overall_header.html

PHPBB3-9758
[ticket/9758] Removed useless if-conditions to include functions.php

PHPBB3-9758
[ticket/9758] Error because of missing functions_display.php fixed

PHPBB3-9758
[ticket/9758] Optimises the html code of avatar image in header

PHPBB3-9758
[ticket/9758] Fixed bug in mcp_warn.php

PHPBB3-9758
[ticket/9758] Adding impr. for overall_header display of avatar and username

PHPBB3-9758
[ticket/9758] Removed the needless space after first ENDIF

PHPBB3-9758
[ticket/9758] Adds id and changes filter to fix travis CI test

PHPBB3-9758
[ticket/9758] Slims the line 4775 in includes/functions.php

PHPBB3-9758
[ticket/9758] Remove unnessary if-question for include functions_display

PHPBB3-9758
[ticket/12043] Sort Extensions by Display Name in ACP Extension mananger

PHPBB3-12043
[ticket/12043] Correct try/catch exceptions for invalid extensions

PHPBB3-12043
[ticket/12322] CSS classes for postprofile-profile <dd> items

There is no subsilver2 equivalent for this commit

PHPBB3-12322
[ticket/12043] Fix order of disabled extensions in unit tests

PHPBB3-12043
[ticket/12324] Correctly create di container if config/ is missing from update/

PHPBB3-12324
[ticket/12316] Add Build Status Icon for develop-ascraeus to README.md

PHPBB3-12316
[ticket/12328] Add Template Event index_body_stat_blocks_after

PHPBB3-12328
[ticket/12329] Add <div> container to index blocks (stats, etc.)

PHPBB3-12329
Merge remote-tracking branch 'Elsensee/ticket/12324' into develop-ascraeus

* Elsensee/ticket/12324:
  [ticket/12324] Correctly create di container if config/ is missing from update/