Allow group to inherit access from other group
It is common that we need to create a group that has the same access rights than an existing one but with some extra. For example all the "admin" groups from modules like group_sale_admin
which should have the same access than group_sale
.
For now usually we just add the extra access to the group and expect the user to set also the base group so both accesses are applied. This is not great because the end user may not know this "rule" and may be astonished that a sale admin can no see the "Sales" menu (because he is not in the sale group).
I propose to add a parent field on Group which makes this group inherit the access from the parent (and all recursive parents).