previewer: fix folders identifiers in zip archive

Reported-by: Konstantinos Kostis <konstantinos.kostis@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
oauth2server: addition of translatable strings

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
oauth2server: confidential and public clients

* Adds option to new application form to ask user for client type.
  (addresses #2113)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>