Updated regex that modifies date code to make letter after date optional
Changed validation SubtitleMarkNoSignificantChanges to only look at caption lengths, not subtitle marker positions.
When loading and evaluating the Rtfile, don't open it with the 'b' flag. This forces external encoding to ASCII-8BIT. We want to open it as UTF-8, so that multibyte characters in `setting :pdf_export_header_text` work.
PDF export: Updated truncation of title in header to make all-caps titles fit
PDF export: remove lines in footer for non-primary repos