Todo:

For version 1.1:

  - Use pixel loaders provided by Qfits (new in Qfits 4.0.0) and get rid
    of the qfits_ext extension module.

  - Change module resampling so that it does not rely on module e_error.
    Get rid of module e_error.

  - Limited restructuring and cleanup of source modules.


For version 2.0:

  - Cleanup program design.
  
  - Rewrite several source modules.

  - Better usage of new Qfits functionalities.