radius-admin: db: explicit pagination extension
radius: let the devs handle Sequel::DatabaseError

At least temporarily...

There's need to face to actual removal (that time has arrived, apparently...)
of a deprecated feature... A vague idea of the problem could be found at
https://github.com/jeremyevans/sequel/pull/373#issuecomment-1792266
radius-admin: Sequel: go over deprecated 'AS'

Users' page
Sequel.aliases

and use in RADIUS user page
radius-admin: Sequel.aliases for remaining user.rb
radius-admin: group (get): use Sequel.{as|aliases}
Sequel.aliases for radius/accounting.rb
radius-admin: Sequel.like in group.rb
radius-admin: user delete form
radius-admin: delete user (still buggy...)
radius-admin: users: fix another missing Sequel.as
radius-admin: remove stale group membership

on user deletion
version bump 2013.09