[ticket/11966] Add header navigation template events to Subsilver2

Add the overall_header_navigation_append / prepend template events
used in Prosilver to subsilver2 as well. This will allow extensions to
add Nav Links to Subsilver2.
http://tracker.phpbb.com/browse/PHPBB3-11966

PHPBB3-11966
[ticket/12046] Use PHP_BINARY environment variable in PHP lint test.

PHPBB3-12046
[ticket/11966] Merge branch 'develop' into ticket/11966

PHPBB3-11966
[ticket/12077] Fix strict standards error.

PHPBB3-12077
[ticket/12077] Add missing space after template block name.

PHPBB3-12077
[ticket/12077] Fix another strict standards error.

PHPBB3-12077
[ticket/12104] Replace shadow topics $sql with $sql_array for better Event handling

PHPBB3-12104
[ticket/12104] Remove empty LEFT_JOIN array

PHPBB3-12104
[ticket/12104] Remove newline before WHERE parameter

PHPBB3-12104
[ticket/12104] Update the event's doc block to reflect new variable

PHPBB3-12104
Merge pull request #1945 from VSEphpbb/ticket/12104

[ticket/12104] Replace shadow topics $sql with $sql_array for better Eve...
Merge pull request #1938 from prototech/ticket/12077

[ticket/12077] Ensure that valid upload methods are presented to user in language packs page.
Merge remote-tracking branch 'remotes/bantu/ticket/12046' into develop-olympus

* remotes/bantu/ticket/12046:
  [ticket/12046] Use PHP_BINARY environment variable in PHP lint test.
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/12046] Use PHP_BINARY environment variable in PHP lint test.
Merge pull request #1809 from VSEphpbb/ticket/11966

[ticket/11966] Add header navigation template events to Subsilver2
[ticket/12011] Align ACP tabs to the right and separate ACP content from menu.

PHPBB3-12011
[ticket/12011] Stop the last post column from dropping to a second line.

PHPBB3-12011
[ticket/12011] Correctly align the pagination icon in topic rows.

PHPBB3-12011
[ticket/12011] Align PM/post titles to the right.

PHPBB3-12011
[ticket/12011] Fix the overlapping unapproved post icon.

PHPBB3-12011