winrm transport should use a single (or minimal) shell when transferring files. transfer via a zip file to optimize round trips

This can significantly improve file upload performance over winrm. It eliminates a authentication handshake and winrs process creation for each call and compresses the files to a single contiguous block to rudece the number of round trips necessary to transfer the files. winrm limits roundtrips to 8k chunks do optimizing the payload is crucial.