Merge pull request #13938 from owncloud/deprecate-iappconfig

Deprecated \OCP\IAppConfig - add missing methods to IConfig

diff --cc apps/files_sharing/tests/api.php
Simple merge

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

diff --cc lib/private/legacy/appconfig.php
Simple merge

diff --cc lib/private/share/helper.php
Simple merge

diff --cc lib/public/iappconfig.php
Simple merge

diff --cc lib/public/iconfig.php
Simple merge

diff --cc tests/lib/share/share.php
Simple merge