owncloud/core

Change: Added federated shares scan cronjob depreciating incoming-shares:poll

We've fixed the behavior for federated shares poll command that in certain conditions
was producing stale filecache entries, and replaced it by fed shares scan cronjob.

ScanExternalShares that was added is a background job used to scan external shares
(federated shares) that are eligible for scanning to ensure integrity of the
file cache - i.e. satisfy preconditions as last user login,
last scan and whether root storage updated.

https://github.com/owncloud/core/pull/37391
https://github.com/owncloud/enterprise/issues/3902
https://doc.owncloud.com/server/admin_manual/configuration/files/federated_cloud_sharing_configuration.html