Change display of cancelled users, fix edit link

It’s confusing showing green ticks for cancelled invites. This commit
changes the appearance so that only pending or active users (ie those
that could actually do some damage) get green ticks.

Also fixes missing edit links caused by instances of `User` having
`.state` but instances of `InvitedUser` having `.status`.

Right now these are two separate lists. Which makes it harder to add
improvements that will make large numbers of users easier to manage.

app/notify_client/models.py

@@ -184,6 +184,8 @@ class InvitedUser(object):
         self.auth_type = auth_type
 
     def has_permissions(self, *permissions):
+        if self.status == 'cancelled':
+            return False
         return set(self.permissions) > set(permissions)
 
     def __eq__(self, other):