directories 
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extract   all extract, circle and box command
grid      all grid command

readwr    read write save restore saoimage , dir   
include   all includes used in more than one directory 

hdrmap    internal header and memory allocation
 
lib       general routines used by more than one commands
          in the different directiories

pgadd     low level image plot routine

hdrinfo   chheader,ra2pix,pix2ra,cey,show,header, info
          skyview, skymap, finding_chart

implot    disp, contour, scale,levels, smc, title, label, vplabel
          cct, cl, cda, viewport, close_pg_window, save-levels, cpd

imstat    remove-sources, detect, sosta, psf, smooth, background
          vignetting, centroid 

imoper    rebin, resize,slice,rotate,sum_image,polygon,rescale,flip