Merge pull request #13425 from owncloud/phpdoc_cleanup

Cleanup of PHPDoc return types

diff --cc apps/files_sharing/lib/controllers/sharecontroller.php
Simple merge

diff --cc apps/user_ldap/lib/access.php
Simple merge

diff --cc lib/private/app.php
Simple merge

diff --cc lib/private/files/cache/cache.php
Simple merge

diff --cc lib/private/tags.php
Simple merge