Fixed issue with fflush with progress info.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
Improved messages, formats, using KiB instead of bytes. Added error handler for sftp_handle. Displaying info about version and copyright.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>