merge master into filesystem

3rdparty/MDB2/Driver/Manager/pgsql.php

3rdparty/MDB2/Driver/Manager/sqlite.php

3rdparty/MDB2/Driver/Reverse/pgsql.php

3rdparty/MDB2/Driver/pgsql.php

apps/calendar/ajax/importdialog.php

apps/calendar/appinfo/info.xml

apps/calendar/export.php

apps/calendar/img/Icon License

apps/calendar/img/icon.png

apps/calendar/img/icon.svg

apps/calendar/import.php

apps/calendar/import_tmp/Info

apps/calendar/js/calendar.js

apps/calendar/js/loader.js

apps/calendar/l10n/ar.php

apps/calendar/l10n/bg_BG.php

apps/calendar/l10n/ca.php

apps/calendar/l10n/cs_CZ.php

apps/calendar/l10n/da.php

apps/calendar/l10n/de.php