use  "stock definition supply" which overwrite default parameter in
purchase supply for the date included in "valid from" et "valid until"
if the value is not defined in "stock defintion supply", the default
parameter is used

Change management is used to manage changes related to transformation
Inside a Change management, transformation change defines the
changes related to previous transformation
An alarm is launched one time per day to apply changes
When it's called, previous transformations are invalidated and new one is
created
User can jump from transformation change to related transformation and transformation to related transformation change

This allow to use transformation as predicate

When a first migration was reverted for any reason (e.g. ConflictError),
the assertion failed because __setstate__ was not called yet to fix the
class back to the old one.

user should use solve divergence for split and defer