SDFITS files in LMTOY

[teuben]

There has been a long standing desire to export our calibrated spectra as an SDFITS file.

The gridder that can read sdfits has been writting (slgridder), but may have diverged in places with the current spec_driver_fits, which reads the old style netCDF file.

There is a script (sp2sdfits) to convert a FITS spectrum into an SDFITS file, but this is probably not the ideal export format for simple spectra. Perhaps useful for RSR spectra?

[teuben]

new proposal: let each instrument enumerate the files that need to go into the _SDFITS.zip file for archiving. wildcards are allowed. For RSR, in order to avoid a nearly empty ZIP file, use an upgraded version of sp2sdfits that implements the --rsr option.