[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
[ticket/12962] Add setup-phantomjs-server.sh

PHPBB3-12962
[ticket/12962] Mark test skipped when phantom server not running

PHPBB3-12962
[ticket/12962] Start phantomjs on travis in background

PHPBB3-12962
[ticket/12962] Dump server output to /dev/null

PHPBB3-12962
[ticket/12962] Force language=en for UI tests installation

PHPBB3-12962
[ticket/12962] Run tests for all databases on Travis

PHPBB3-12962
[ticket/12962] Fix whitespace characters

PHPBB3-12962
[ticket/12962] Add facebook/webdriver dependency

Create a new composer.json for tests dir and add
facebook/webdriver dependency

PHPBB3-12962
[ticket/12962] Install test dependencies on travis

PHPBB3-12962
[ticket/12962] bootstrap functional and ui test when php >5.3.19

PHPBB3-12962
[ticket/13126] Improve the feedback when running the migrations

PHPBB3-13126
[ticket/13126] Extends migrator_output_handler instead of using a closure

PHPBB3-13126
[ticket/13126] Move migrator_output_handler to an interface

PHPBB3-13126
[ticket/13126] Change messages verbosity levels

PHPBB3-13126
[ticket/13126] Fix tests

PHPBB3-13126
[ticket/13193] Add link to post count in PMs

PHPBB3-13193