bundle2: capture transaction rollback message output (issue4614) The output from the transaction rollback was not included into the reply bundle. It was eventually caught by the usual 'unbundle' output capture and sent to the client but the result was out of order on the client side. We now capture the output for the transaction release and transmit it the same way as all other output. We should probably rethink the whole output capture things but this would not be appropriate for stable. The is still multiple cases were output failed to be properly capture, they will be fixed in later changesets.