--bandwidth output

[donald]

--bandwidth output may be intermingled with delayed stderr output from (e.g. 'mkdir') the remote side.

A (the only?) way to fix this would be to generate the --bandwidth output on the receiving side.

Additionally, the time measurement is wrong, because the sender writes the file data asynchronously and just continues with the following files when the transfer is finished. The actual delay caused by the data transfer may occur a long time later, when the network pipeline is finally filled and stalls.. Again, this could be fixed by creating the --bandwidth output on the (synchronous) receicing side.

However, for now we want to state protocol-compatible with pmirror.