[ticket/11331] Inform user that double dots will be stripped from avatar paths

PHPBB3-11331
[ticket/12672] Make tab intercept; CB for keypress only react without key mods

Changed the callback of keypress inside the <textarea> for the posting
such that, if key 9 is pressed (tab character) and ctrl, shift, alt and meta
are not pressed the tab is placed. Otherwise, nothing is made and default is
not prevented.

PHPBB3-12672
[ticket/12669] Add core event to the function display_forums()

Add core event to the function display_forums()
in includes/functions_display.php to allow assigning additional template data
for every forum, f.e. additional forumrow subloops.

PHPBB3-12669
[ticket/12673] IMAGETYPE_SWC might be missing when SWC is not supported.

PHPBB3-12673
Merge remote-tracking branch 'bantu/ticket/12673' into develop-ascraeus

* bantu/ticket/12673:
  [ticket/12673] IMAGETYPE_SWC might be missing when SWC is not supported.
[ticket/12675] Fix code sniffer complaints introduced by recent commits

PHPBB3-12675
Merge pull request #2555 from marc1706/ticket/11331

[ticket/11331] Inform user that double dots will be stripped from avatar paths
Merge pull request #2561 from marc1706/ticket/12675

[ticket/12675] Fix code sniffer complaints introduced by recent commits

* marc1706/ticket/12675:
  [ticket/12675] Fix code sniffer complaints introduced by recent commits
Merge pull request #2556 from brunoais/ticket/12672

[ticket/12672] Make tab intercept; CB for keypress only react without key mods

* brunoais/ticket/12672:
  [ticket/12672] Make tab intercept; CB for keypress only react without key mods
[ticket/12660] Improve check for when phpinfo() is disabled.

PHPBB3-12660
Merge pull request #2548 from bantu/ticket/12660

[ticket/12660] Improve check for when phpinfo() is disabled.
Merge branch 'develop-olympus' into develop-ascraeus

# By Andreas Fischer
# Via Andreas Fischer (1) and Dhruv Goel (1)
* develop-olympus:
  [ticket/12660] Improve check for when phpinfo() is disabled.
[ticket/12677] Replace ‘thread’ with ‘topic’ in functions_display comment

PHPBB3-12677
Merge branch 'k0nsl-ticket/12677' into develop-ascraeus

* k0nsl-ticket/12677:
  [ticket/12677] Replace ‘thread’ with ‘topic’ in functions_display comment
Merge pull request #2554 from rxu/ticket/12669

[ticket/12669] Add core event to the function display_forums()

* rxu/ticket/12669:
  [ticket/12669] Add core event to the function display_forums()
[ticket/12668] Add subforums_row to core.display_forums_modify_template_vars

Add subforums template data array to
'core.display_forums_modify_template_vars' event
to allow extensions to modify it if needed.

PHPBB3-12668