Fixes an issue when uploading files to external storage when recovery
keys are enabled

The Util class only works with real users, so instantiating it with the
virtual recovery key user or public key user can cause issues.

Whenever a file is shared with others or with link, a delete button used
to be visible that triggered a direct deletion.

This button has been removed to avoid accidental deletion from people
who might believe it was an unshare button. Unsharing is still possible
inside the share dropdown.

Fixes the OCS capability API at /ocs/v1.php/cloud/capabilities

$file only contains the filename and not the absolute path, that means that files in a subdirectory will not get properly resolved and an empty filesize is returned.

This feature only exists on master.

We don't support direct updates from older ownCloud versions except the previous one therefore this code is unused and can be removed.

This PR removes phpass and migrates to the new Hasher interface.

Please notice that due to https://github.com/owncloud/core/issues/10671 old hashes are not updated but the hashes are backwards compatible so this shouldn't hurt.
Once the sharing classes have a possibility to update the passwords of single shares those methods should be used within the newHash if block.

Sometimes there are bugs that cause setupFS() to be called for
non-existing users. Instead of failing hard and breaking the instance,
this fix simply logs a warning.

fixes download issue introduced by #10755

Conflicts:
	apps/files_sharing/public.php

This fixes an issue when a subdir has the same name as its parent, it
would get exluded from the list.

* otherwise it will always think it hits the limit and need another round to fetch additional results

ownCloud passes us a Unix time integer, but the GDrive API wants
an RFC3339-formatted date. Actually it wants a single particular
RFC3339 format, not just anything that complies will do - it
requires the fractions to be specified, though RFC3339 doesn't.

This resolves issue #11267 (and was also noted by PVince81 in
reviewing PR #6989).

the real file and the part file, because some information from the part file
might be needed later