[IMP] ir.ui.menu: enable `parent_store` to allow using the `child_of` operator efficiently when loading the menu hierarchy
[IMP] ir.ui.menu: enable `parent_store` to allow using the `child_of` operator efficiently when loading the menu hierarchy

The menu loading logic in openerp-web was adapted to use
`child_of`.

akretion/openerp-server,akretion/openerp-server,akretion/openerp-server