Add Payone Plugin Community Store Version 2.3.1
Append session when forwarding payment requests
Remove whitespaces from bank account information in ParamBuilder

Users often enter their bank account detials containing whitespaces, which is not allowed by the FinanceGate API.
Use correct shipping costs when building request to Payone's API
Transmit customernumber when creating API requests
Transmit correct vatid when creating API requests
Transmit no vat for articles to payone when the order is tax free

Squashed by @samuelvogel with "Fix wrong computation of tax free flag" from @stefanheppenheimer
Fix error in risk management
Calculate actual tax rate of shipping costs
Don't require matching countries for tax-free company orders

Merge Shopware PR: https://github.com/ShopwareAG/shopware-4/pull/187