take the etag of child mounts into account for the folder etag

apps/files_sharing/appinfo/app.php

apps/files_sharing/appinfo/application.php

apps/files_sharing/lib/mountprovider.php

apps/files_sharing/lib/propagation/changewatcher.php

...files_sharing/lib/propagation/grouppropagationmanager.php

apps/files_sharing/lib/propagation/propagationmanager.php

apps/files_sharing/lib/propagation/recipientpropagator.php

apps/files_sharing/lib/sharedmount.php

apps/files_sharing/lib/sharedpropagator.php

apps/files_sharing/lib/sharedstorage.php

apps/files_sharing/tests/grouppropagationmanager.php

apps/files_sharing/tests/testcase.php

lib/private/files/cache/cache.php

lib/private/files/cache/changepropagator.php

lib/private/files/cache/propagator.php

lib/private/files/fileinfo.php

lib/private/files/storage/common.php

lib/private/files/storage/storage.php

lib/private/files/storage/wrapper/wrapper.php

lib/private/files/view.php