Add warning when moving lot which decrease quantity below zero
Prerequisite:
A product with lot enabled. The lot is required for production.
Steps to reproduce:
1. Create two lots (e.g. X01 and X02) for the product, and put one
unit for each lot on stock (buying or inventory)
2. Create a production with two units of the product at the input
side
3. Enter the lot X01 for the two units.
4. Finish the production.
5. Look at the inventory. There is now an amount of -1 for lot X01,
and an amount of +1 for lot X02
In my understanding, this should not be possible. The production
should be prevented from being done in this case.