Restricted users (#4334): initial implementation

* Add User.IsRestricted & UI to edit it

* Pass user object instead of user id to places where IsRestricted flag matters

* Restricted users: maintain access rows for all referenced repos (incl public)

* Take logged in user & IsRestricted flag into account in org/repo listings, searches and accesses

* Add basic repo access tests for restricted users

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

models/fixtures/user.yml

@@ -275,7 +275,7 @@
   avatar_email: user17@example.com
   num_repos: 2
   is_active: true
-  num_members: 2
+  num_members: 3
   num_teams: 3
 
 -
@@ -463,3 +463,18 @@
   num_following: 0
   is_active: true
 
+-
+  id: 29
+  lower_name: user29
+  name: user29
+  full_name: User 29
+  email: user29@example.com
+  passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
+  type: 0 # individual
+  salt: ZogKvWdyEx
+  is_admin: false
+  is_restricted: true
+  avatar: avatar29
+  avatar_email: user29@example.com
+  num_repos: 0
+  is_active: true