- The gdal ghost area optimisations can be disabled, and will not be
  emitted for PlanarConfiguration=Separate, as it is not supported by
  gdal
- Each IFD may now reference only a single mask
- The IFD structure is now exported and can be used to hand-craft an
  expected COG from dynamic data
- Encoding (little vs. big endian) is now configurable
- For PlanarConfiguration=Separate files, it is possible to fine tune
  the layout/interlacing of each plane's tiles and mask tiles,
  supporting tile orders like r1,g1,b1,r2,g2,b2 (the default), or
  r1,r2...g1,g2...b1,b2 or even r1,g1,r2,g2,...rn,gn,b1,b2