fixes#1362
Ignoring qty_available for phantom products prevents double counting the
qty_available of components.
Creating planned orders for phantom products is simpler than recursively
exploding phantom BOMs. This also makes it easier to analyze the planning data
generated by the MRP calculation.
For each MRP Parameter or for each Product in a MRP Area, we will be able to add a MRP Planner. Once this planner is set, he can filter himself in the MRP Parameters view, MRP Inventory view or MRP Planned Orders view.
* 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.
* Add menu entry for planned orders
* Add button to navigate from planned orders to linked manufacturing orders
* Add action to convert planned orders to fixed
* When changing the due date in a planned order the release date is recomputed
