Update: rework access control to be automatic based on is_* roles in the t_users...

Update: rework access control to be automatic based on is_* roles in the t_users table

Instead of trying to use select queries on every statement based on a users role, have the database automatical grant/revoke roles based on column settings in the s_tables.t_users table.
u_public and r_public have been renamed to be u_reservation_public and r_reservation_public to keep all roles self-contained.
name_machine fields should now only allow word characters.