Shipment total manager (JS) doesn't work correctly with tax

[mrbrdo]

When you are using tax included in price setting, the ShippingTotalManager will subtract tax difference between methods twice, causing wrong calculation in the checkout shipping step.
The problematic line is
var newOrderTotal = orderTotal + this.totalShipmentAmount(newShipmentTotal, oldShipmentTotal) + (newTaxTotal - oldTaxTotal)
If the last part is removed, it works correctly when Store prices are set to include tax (as is usual in EU).