Add new modules for simplified transfer of goods between stock locations...

Add two new modules to ease creation of pickings and corresponding stock moves for transfer of goods between stock locations.
1. Wizard to select source and destination module and goods to transfer
2. Customization: Model the 
transfer of goods via a dedicated transit stock location (ship, truck etc.). This creates 2 separate pickings per transfer. One to move goods from source location to transit location and another one to receive goods from transit location into destination.

![bildschirmfoto vom 2014-12-12 17 40 37](https://cloud.githubusercontent.com/assets/1388003/5415235/0a204908-8226-11e4-9fb5-a59526bbcb43.png)
Use self.pool[]