SFTP upload / download not support returncarried adding /removint

SFTP version 4 started supporting message transmission where line breaks are automatically converted to match the target machine's line break format. This feature was supported in the old Cobalt, but apparently Rencil does not support it automatically. This likely works at the protocol level, so that by sending an ASCII-type message, the receiving server performs the conversion if necessary. Cobalt's version always performs this conversion, even between Win-Win machines.