ZODB Components: Add unit test for upgrade of bt5 from filesystem to ZODB.
ZODB Components: Must be able to really delete a Component and not only in 'deleted' state.

Folder_delete calls Workflow 'delete_action' if the object has any Workflow
History. Before, component_validation_workflow was acting like
validation_workflow for deleting objects, e.g. 'delete_action' triggers
'delete' state which is fine for normal documents but not Components.
ZODB Components: Ensure that Permissions on Developer can be updated later (through Filesystem).

In 5d9c30e, Permissions were set in ComponentTool __init__ and it could not be
modified later on because it is set directly in the ZODB. Moreover,
Permissions could be modified after execution by modifying attributes.
ZODB Components: Revert partially "ZODB Components: Fix bootstrap of migrated bt5s.".

This reverts the following part of 5d9c30e:

* 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.

This obviously does not work as the Document can be used as Type Class and
also because tool_item is required before portal_types for example (see
test_type_provider).

When bootstrapping erp5_core and installing for example an Extension
Component, this will try to load Extension Component Portal Type which does
not exist yet but fallback on its document class instead, which is enough
until Extension Component Portal Type is installed.