Quality status of stock for OpenERP

--- Proposed principle ---
3 status are defined :
- A: accepted, normal quality goods
- R: goods refused, scrap
- U: status unknown, goods awaiting a user's action to decide status (for example quality controls)
Only the stock with status "A" is usable in other modules (sales, manufacturing...)
The status of the goods in the warehouse is changed by recording a stock move with different source/destination status.

--- Changes needed ---
Implement as a new module.

Add 2 fields to Stock Moves : "quality status of source" & "quality status of destination", both required, default "A", can be manually set changed to "U" or "R".
Add the same filed to Stock Inventory Lines and take it into account when computing stock level differences.
At module installation time, all existing rows must be set to the status "A".

In both Products and Stock Locations:
- redefine the "available quantity" as the real stock with status "A".
- redefine the "virtual stock" as virtual stock with status "A" or "U".
This way, goods with status "U" or "R" are excluded from every modules using Stock Moves.
Add 2 more function fields :
- quantity in status "U" (real stock only)
- real stock in status "R" (real stock only)

Add an integrity rule: Stock Moves with destination status != "A" and destination location type "production" or "customer" can never be "done"