Make upgrades appear in undo form again.

The transaction note fix in 1.7.4 caused upgrade transaction to not appear in the undo form anymore.

Setting the transaction description directly did somehow cause the transaction to no longer appear in the undo form.
The implementation is therefore changed to use the transactions `note` method instead. It is only called once because `note` appends each message to the existing description.

The new implementation no longer overrides previously noted messages and respects the length of the existing transaction description regarding its length.