Add on_inventory_retry_assign

A module that check the availability of the available delivery orders
when an inventory is set to 'done'. If the quantity of a product has
been reduced, delivery orders could become unavailable.
updated translations
Add test for on_inventory_retry_assign, sort pickings by min_date
Use CamelCase for class name
Renamed on_inventory_retry_assign to stock_inventory_retry_assign
Better wording as suggested by @pedrobaeza
Rename on_inventory_retry_assign to stock_inventory_retry_assign in translations
Merge pull request #3 from guewen/7.0-on_inventory_retry_assign

[ADD] stock_inventory_retry_assign