* keept description of planned orders verbose.
* make it translatable in most cases.
* while grouping demand include the product in the description.
* add `origin` field not mrp moves and planned orders. Fill it
with top level demand origin.
* You can know integrate with different forecasting mechanisms.
As a consequence integration with stock_demand_estimate is moved
to a new module (mrp_multi_level_estimate).
* As agreed by the authors, the module is re-licensed to LGPL-3.
