Without this patch filtering for the "_everyone" (empty) group did not work for subadmins.

Fixes itself.

* reason: nice to know before password change in user management
* restore is possible:
	* encryption is disabled
	* encryption is enabled, admin and user has checked the
	  restore option
* if not possible:
	* highlight users row in red once the admin wants to change the password
	* show also a little tipsy

Previously when $gid was empty the users were not filtered at all. Rendering the search function in the user management pretty useless.

Fixes itself

* causes the first load after the initial load to hide some users in the viewport
  and showing them again, but with a scrolled up viewport
* causes higher load for nearly never visible effects
* fixes #12962

* gives the user the chance to verify it's mail address
  and display name
* ref #12823
* fixes #13393

adapt decrypt all and restore/delete key backups to the new folder structure for encryption key introduced with OC8