FITS i/o

There have been ongoing problems with exchanging single spectra in FITS format between SPECX and CLASS. We (Remo Tilanus and I) believe that this has now been cured, following minor changes to both programs (with the cooperation of the CLASS authors at IRAM). Certainly SPECX now seems to produce valid CLASS spectra. I have also resurrected John Richer's FITS reader, and with a great deal of hacking turned it into a standard command that reads disk-FITS spectra (SIMPLE=.TRUE. only) into the X position of the stack. This command is READ-FITS-SPECTRUM -- open the FITS file with OPEN-FITS-FILE and close it afterwards with CLOSE-FITS-FILE as before (note that the names of these commands have been changed from OPEN-FITS-OUTPUT-FILE and CLOSE-FITS-OUTPUT-FILE respectively).

FITS maps are more of a problem. Claire Chandler has recently modified WRITE-FITS-MAP to make it compatible with AIPS (it always used to be, so I assume that AIPS has changed too...), but this is probably not compatible with CLASS. We may eventually need separate commands to write FITS maps for different targets.