[ticket/12941] Add sami.conf.php for Travis CI.

PHPBB3-12941
[ticket/12941] Check for Sami parse errors on Travis CI.

PHPBB3-12941
[ticket/12938] Remove the 'Download all attachments' feature.

PHPBB3-12938
[ticket/12943] Add core.phpbb_generate_debug_output core event

Add core.phpbb_generate_debug_output core event to allow extensions
outputting additional debug info.

PHPBB3-12943
[ticket/12949] Check if mime_content_type is actually callable

PHPBB3-12949
[ticket/12941] Fix remaining Sami complaints.

PHPBB3-12941
[ticket/12953] Page title not updated when notifications are marked as read

PHPBB3-12953
[ticket/8064] Change the collation of topic_first_poster_name

PHPBB3-8064
Merge pull request #2849 from bantu/ticket/12941

[ticket/12941] Check for Sami parse errors on Travis CI.

* bantu/ticket/12941:
  [ticket/12941] Fix remaining Sami complaints.
  [ticket/12941] Check for Sami parse errors on Travis CI.
  [ticket/12941] Add sami.conf.php for Travis CI.
[ticket/12938] Remove functional tests for 'Download all attachments'.

PHPBB3-12938
Merge pull request #2851 from marc1706/ticket/12949

[ticket/12949] Check if mime_content_type is actually callable
Merge remote-tracking branch 'github-nicofuma/ticket/8064' into develop-ascraeus

* github-nicofuma/ticket/8064:
  [ticket/8064] Change the collation of topic_first_poster_name
Merge pull request #2852 from bantu/ticket/12938

[ticket/12938] Remove the 'Download all attachments' feature.

* bantu/ticket/12938:
  [ticket/12938] Remove functional tests for 'Download all attachments'.
  [ticket/12938] Remove the 'Download all attachments' feature.
Merge pull request #2855 from Geolim4/ticket/12953

[ticket/12953] Page title not updated when notifications are marked as read

* Geolim4/ticket/12953:
  [ticket/12953] Page title not updated when notifications are marked as read
Merge pull request #2846 from rxu/ticket/12943

[ticket/12943] Add core.phpbb_generate_debug_output core event

* rxu/ticket/12943:
  [ticket/12943] Add core.phpbb_generate_debug_output core event
[ticket/12962] Add facebook/webdriver dependency

PHPBB3-12962
[ticket/12962] Add initial class for ui_testing

PHPBB3-12962
[ticket/12962] Add quick-links JS test

PHPBB3-12962
[ticket/12962] Add UI tests to phpunit.xml.dist

PHPBB3-12962
[ticket/12962] Run UI tests on Travis-mysql

PHPBB3-12962