This avoids calls to the autoloader (or chain of autoloaders) to see if
for example 'principalPrefix' class can be found. While we already know
it is a string.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Joas Schilling <coding@schilljs.com>

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

To align with https://github.com/nextcloud/server/issues/2043#issuecomment-287348294


This would mean that AppContainers only hold the AppSpecific services

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

* \OC\OCSClient
* \OC\Preview
* \OC\PreviewManager
* \OC\Repair
* \OC\RepairException
* \OC\Search
* \OC\ServerContainer
* \OC\ServerNotAvailableException
* \OC\ServiceUnavailableException
* \OC\Setup
* \OC\Streamer
* \OC\SubAdmin
* \OC\SystemConfig
* \OC\TagManager
* \OC\Tags
* \OC\TempManager
* \OC\TemplateLayout
* \OC\URLGenerator
* \OC\Updater

Backends are registered to the BackendService through new data
structures:

Backends are concrete classes, deriving from
\OCA\Files_External\Lib\Backend\Backend. During construction, the
various configuration parameters of the Backend can be set, in a design
similar to Symfony Console.

DefinitionParameter stores a parameter configuration for an external
storage: name of parameter, human-readable name, type of parameter
(text, password, hidden, checkbox), flags (optional or not).

Storages in the StoragesController now get their parameters validated
server-side (fixes a TODO).

This reverts commit 6a1a4880.