Use stdin and stdout instead of files for arguments and results

[harendra-kumar]

Use stdin for input and stdout for output of the rpc function. This will become a true unix style utility and we can avoid the complications of creating files. Moreover, we will be able to stream data without any effort. We already have a way to call an executable via ssh and supply it input on stdin and collect the output on stdout. Using that we can just plugin in the remote function in a local streaming pipeline.