Merge master => 3.0

CHANGELOG.md

CONTRIBUTING.md

README.md

composer.lock

core/CronArchive.php

core/DataTable.php

core/Piwik.php

core/Plugin/ConsoleCommand.php

core/Settings/SystemSetting.php

js/piwik.js

lang/am.json

lang/be.json

lang/bg.json

lang/cs.json

lang/da.json

lang/de.json

lang/el.json

lang/fa.json

lang/fi.json

lang/fr.json