[ticket/7707] Add get_username_string() where possible

PHPBB3-7707
[ticket/7707] Remove unnecessary variables

PHPBB3-7707
[ticket/7707] Add get_username_string() once more

PHPBB3-7707
[ticket/7707] Remove unnecessary variables

PHPBB3-7707
[ticket/11962] Resize posted images to fit and give them a class

PHPBB3-11962
[ticket/12333] Add Template Event overall_header_body_after

PHPBB3-12333
[ticket/12333] Change event name

PHPBB3-12333
[ticket/12339] Add Event core.page_header_after

PHPBB3-12339
[ticket/7707] Add comma to last entry of arrays

PHPBB3-7707
[ticket/12342] Use prop() instead of attr() for boolean properties

PHPBB3-12342
[ticket/12342] Fix Find a member show / hide script

PHPBB3-12342
[ticket/12342] Fix the Custom Dates function in UCP Prefs Global

Function was being called before dE() function exists,
causing it to fail. Should be called when the page/window
is ready.

PHPBB3-12342
[ticket/10851] Set disallowed content to empty array if checking is disabled

The disallowed content defaults to a standard set of mimetype triggers by
default. If one doesn't want to check the attachments mimetype triggers then
we need to set the disallowed content to an empty array.

PHPBB3-10851
[ticket/12342] Remove spinner and fix useage of ajax on memberlist

PHPBB3-12342
[ticket/12318] Revert "Pin HHVM version to 3.0.0~precise."

This reverts commit f6614f2078740675ca0228b348500991888c2140 as the install
command started failing with "Version '3.0.0~precise' for 'hhvm' was not found"
in the meantime.

PHPBB3-12318
Merge remote-tracking branch 'bantu/ticket/12318' into develop-olympus

* bantu/ticket/12318:
  [ticket/12318] Revert "Pin HHVM version to 3.0.0~precise."
Merge branch 'develop-olympus' into develop-ascraeus

* develop-olympus:
  [ticket/12318] Revert "Pin HHVM version to 3.0.0~precise."
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12318] Revert "Pin HHVM version to 3.0.0~precise."
Merge branch 'ticket/10851' into ticket/10851-ascraeus
[ticket/10851] Add unit and functional tests for checking attachments

These tests will make sure that fileuploads now work as expected regarding
the check for disallowed content.

PHPBB3-10851