[trunk] Finishing stock_planning module for 6.0

Finish the stock_planning module which was improved a lot by me some time ago (yet for 5.2). Now according to design changes some menu are not connected to parents and module needs some finishing.
If anybody plan to work on it please notice me.
To do:
1. Create period wizard menu
Do you agree to make it in Inventory Management - Configuration as Stock periods?

2. Create forecast menu
Do you agree to make it in Sale menu as Quantity Forcast?

3. Current main MPS menu make in Inventory Management - Planning as Manual Planning?

4. Fix the UoM-UoS converting

5. Add helps to actions according to new convention

If it is no objections I will create a branch for it soon.
Can I ask anybody to remove stock_planning module from extra-trunk as new module was promoted to core addons?