bugfix - the change from processing with memory buffers to on-disk allows processing of huge data files, but created a bug. If there were HTML escape codes for newline and line separator characters, the 'scrub-tm' graph converted them to unicode characters in the text. Processing on-disk meant these changes shifted the number of lines and broke source-target alignment. This fix converts newline and separators to spaces that preserve alignment. This restores the functionality that was used in the in-memory buffer processing.