Subdirectorys for Iterator_ALT Procedure include files.

 gen ... Contains the unchanged Generated Code
          some of the generated iterators (that did not work)
          were moved to  Subdirectory gen_deleted
          (gen_deleted is not part of the gap release tar-file)
 
 mod ... Contains the Hand-Modified Code
         for those Plugins where the generated iter_ALT
         Code did not work.
         (their Last-Value Buffer structure did not
          math the PDB-Paraeter description) 

 old ... Contains Hand-Modified (or generated) old
         Iterators.
         (For Plugins that are not part of gimp 1.1.3
          but once were part of gimp 1.0 or prior releases)
          
