There was no "isAdminUser()" function which returned bool. This is
irritiating as there were a loooooooot of places in the code which
checked this itself with `OC_Group::inGroup($uid, 'admin)` - why not
use a function for this?
(Especially if you consider that we might change the group name in the
future, which would lead to problems then)

Additionally, @Raydiation needed such a method for his AppFramework :)

This fixes a problem that prevented app routes from being loaded after ocs_api merge

This reverts commit 9d41322c.

Remove ugly indentation - Trivial

Conflicts:
	apps/files_versions/templates/settings-personal.php

Update CONTRIBUTING.md

Thanks @eMerzh, could be especially needed as there are some platform specific issues like filename encoding under MS Windows

:oops:

Makes it at least better readable for me.

Move openid.php to apps repo

Conflicts:
	settings/routes.php

Add contribution file

- some more code comments
- fixed bug in the expire function, cleanup all_versions array during run. Otherwise it could happen that we try to delete already deleted versions

Enhanced multiSelect

Add security section to admin settings to enable the HTTPS enforcement

Remove setContentTypeHeader()

Remove uneeded file 

This belongs to the apps repo.