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).
When reading in old mount.json files, they do not contain config ids.
Since these are needed to be able to use the UI and the new service
classes, these will be generated automatically.
The config grouping is based on a config hash.
remove minified select2 js
show avatars for users, simpler results
remove unneeded users and groups from settings template
fix css, escape user and group names