* Upon bt5 installation, install portal_type* items before bt5 {Document,
  Extensions...} as corresponding Portal Type are required once they have been
  migrated to ZODB Components.

* Likewise portal_{property_sheets, types}, portal_components must be created
  automatically *before* installing any bt5. This is required when Products
  will be migrated but also for bt5 items before bootstrapping erp5_core bt5.

* Set Permissions in ComponentTool instanciation and revoke all permissions,
  then allow only some of them for security sake.

* When creating ERP5 site with unit tests, add ERP5TypeTestCase to Developer
  Role ASAP so that there is no Permission issue when installing bootstrap bt5
  and test bt5s containing ZODB Components.