Temporarily returning true to all event.hasAdminPermission() calls while we refactor

[skip ci]
Temporarily commenting out all the permissions checking code in CkEditorToolbarHelper while we refactor
Renaming securityService to loginService and stripping all the perms related functionality from it
Fixing temporary botch code to not do permissions checks
Beginnings of permmissions service
Parsing useful permission and config structure into a denormalized form
Documenting overview of permissioning & how to configure roles and permissions

[skip ci]
Adding ability to list permissions for a given user group to the permissions api
Adding ability to list permission keys for a given user
Creating hasPermission() method that always returns true for system users
Actual lookup of permissions against user's groups and roles for the hasPermission() method
A little reshuffling of api methods for better readability
Adding some tests for the hasPermission() method to test that passing in a userId directly will work, rather than relying on logged in user id
Tidying up old redundant preside objects and properties files + adjusting the user and userRole preside objects to be user and userGroup inline with the new model for permissions
Removing the now redundant 'global permissions picker' form control

[skip ci]
Removing old references to the adminSecurityService which no longer exists

[skip ci]
Updating labels + form field layouts for users and groups

[skip ci]
Rechristening all the role management UI to be Group management + making the GUI work for managing users + groups

[skip ci]
Creating a permissions role picker form control

[skip-ci]
Adding a default set of roles + permissions to core

[skip ci]