Add right margin to codestyle file

Defaults to 120, we want 80 apparently
Add public api for mount configurations
Use the mount config api for files_external
Add REST route for user & group management

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.
fix updated URL schema in JS unit tests
Fix deleting selected files in the trashbin
Fix url
Add statuscodes
Merge branch 'initial-work-migrate-to-appframework' of https://github.com/owncloud/core into initial-work-migrate-to-appframework
Merge pull request #12696 from owncloud/trashbin-selected-delete

Fix deleting selected files in the trashbin
React on other statuscodes than 200
Merge pull request #12621 from owncloud/add-right-margin

Add right margin to codestyle file
preserve an asterisk at the start when escaping a search term
add doc
Merge pull request #12704 from owncloud/fix-12647-2

preserve an asterisk at the start when escaping a search term
Merge pull request #12618 from owncloud/initial-work-migrate-to-appframework

Add REST route for managing groups and users
Extract  interaction with config.php into SystemConfig

* 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
@deprecated messages for \OCP\Config and \OCP\AppConfig
use old methods and redirect in deprecated methods
introduce proper interface for deleteAppValue