Actually use Permissions.php functions

[killua-eu]

We have the beautiful https://github.com/vaizard/glued/blob/master/glued/Classes/Permissions/Permissions.php but hardly any code using them (we have this ugly hack testing if user is root instead to have some division). Lets

• actually define permissions for roots, users etc. in the permissions table
• add the sane rules you'd expect glued to have out of the box (i.e. root can do anything) written in migrations
• expand the scope of privileges (table, all objects, object) to include interface parts. i.e. we want to show a menu item only to roots or users with another specific privilege.