certificate manager should always use a \OC\Files\View otherwise we will get problems for different primary storages

Beside some small improvements and bug fixes this will probably the final state for OC8.

To test this you need to set up two ownCloud instances. Let's say:

URL: myPC/firstOwnCloud user: user1
URL: myPC/secondOwnCloud user: user2
Now user1 can share a file with user2 by entering the username and the URL to the second ownCloud to the share-drop-down, in this case "user2@myPC/secondOwnCloud".

The next time user2 login he will get a notification that he received a server-to-server share with the option to accept/decline it. If he accept it the share will be mounted. In both cases a event will be send back to user1 and add a notification to the activity stream that the share was accepted/declined.

If user1 decides to unshare the file again from user2 the share will automatically be removed from the second ownCloud server and user2 will see a notification in his activity stream that user1@myPC/firstOwnCloud has unshared the file/folder from him.

The file:// protocol does not work with curl when an open_basedir is set.

This fixes https://github.com/owncloud/core/issues/12016

Make DateTimeFormatter a service and adjust tests that have been inaccurate

* this needs to be properly fixed by a proper organisation of the base.php
* introduced fixDIInit() in AllConfig that moves the injection
  of DatabaseConnection to a later point in time
* problems mostly because of the autoconfig setup

* keep old static methods - mapped to new ones and deprecated
* removed deleteApp, getUsers, getApps because they are unused
* make AllConfig unit tests more robust against not cleaned up environments

* introduce SystemConfig to avoid DI circle (used by database connection which is itself needed by AllConfig that itself contains the methods to access the config.php which then would need the database connection - did you get it? ;))
* use DI container and use that method in legacy code paths (for easier refactoring later)
* create and use getSystemConfig instead of query() in DI container

First step of a somewhat testable user management. - I know, the JSON returns are in an ugly format but the JS expects it that way. So let's keep it that way until we have time to fix the JS in the future.

Public interface for hashing which also works with legacy ownCloud hashes and supports updating the legacy hash via a passed reference.

Follow-up of https://github.com/owncloud/core/pull/10219#issuecomment-61624662
Requires https://github.com/owncloud/3rdparty/pull/136

It's only reasonable to have proper type hinting here which might even help us to catch bugs.

Remove \OC\DB\ConnectionWrapper, have \OC\DB\Connection implement \OCP\IDBConnection directly instead

suspend encryption proxy when copying skeleton

Subclassed from \OCP\AppFramework\Db\Entity and Mapper,
respectively. This will allow us to also deal with shared tags.

We do not want to follow redirects to other protocols since they might allow an adversary to bypass network restrictions. (i.e. a redirect to ftp:// might be used to access files of a FTP server which might be in a secure zone and not be reachable from the net but from the ownCloud server)

Get final redirect manually using get_headers()

Migrate to HTTPHelper class and add unit tests