fixes #6474
Merge remote-tracking branch 'origin/master'
Add section about fixtures
Update README.md
submodule UI tests
Run AngularJS and piwik.js tests on PHP 5.6 for consistency as there is no added benefit to use 5.3 for this
Delete archives older than yesterday midnight raher than today midnight as we may delete too often otherwise
language update  refs #3430
Merge pull request #6482 from piwik/translationupdates

[automatic translation update] Updated 209 strings in 3 languages (ja, tr, cs)
try to remove version option in case we are uninstalling a dimension and remove a log_conversion column in a VisitDimension only if it implements a conversion
Add better output to screenshot test failure & update UI test submodule.
Updating UI tests moudle.
fixes #6475 use Tracker adapter rather at all times in tracker
Merge pull request #6486 from piwik/bugfix-6475

fixes #6475 use Tracker adapter rather at all times in tracker
2.8.1-rc1
refs #6481 should make sure all dimensions are selectable in report generator
Add save-config option to SetupFixture so access to test data can be saved in new config.ini.php to avoid having to run SetupFixture after needing a fixture for a while.
Fixes #6479, properly set period parameter in subtable & segment requests when period is range in PivotByDimension filter.
Skip couple system tests that randomly fail on mysqli
Fix few integration tests