saveNSx

  Save an .NSx file from an NSx structure (gained by using openNSx)
  Works with file spec 2.3
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  Use: saveNSx(NSx,optionalinputarguments)
    NSx:        The NSx data structure.
    All arguments below are optional:
    Filename:   A complete filepath for the output file.
                Default: CurrentFilename-Modified.NSx