
For developers only:

some notes and caveats on the cdf-to-fits converter

- the B (INT1) type is converted to I (INT2) to deal with the sign bit. this is strictly
  not needed. See old code in testcdf2fits and the supporting routine in convert_uint()
  how to preserve the bit width in clever way of combining bit masking and FITS
  scaling TZERO/TSCAL

- to roughly preserve the size of a CDF file with variant records, it is necessary to
  write out multiple HDU's, each with a different number (NAXIS2) of rows, corresponding
  to the entries (maxRec+1) in the CDF variable.

- each extension is marked 'cdffitsN', where N is the N-th HDU (1 for the pHDU)

- the cdf-to-fits dataformat version we use is stored in an integer keyword 
  CDF-FITS, currently 20 (meaning 2.0)

- the cdf-to-fits software version is encoded in a CVS string CDF2FITS, e.g.
	'$Id: cdf-to-fits.c v1.5 ....'

- it's possible to screw up teh conversion logic for non-native CDF's by giving
  them in the wrong order, or not giving them all. We could enforce a template
  name and parse them all...



A few words about performance:

SNOE_l3_mag.cdf 			   38MB	       1.260u  1.000s  0:08.90 25.3%  
GUVI_im_disk_v008r01_#D5297.L1B.cdf        48MB        1.990u  0.810s  0:20.72 13.5%  
TIDI_PB_2003077000200_200307707.cdf	  182MB	      53.240u 67.240s 11:59.76 16.7%

The last file caused the load on the machine to reach over 4
Here are some conventions you should know about this current
CDF-FITS convention.


- all native CDF files are translated to a FITS BINTABLE. Because the
  zVars are not all filled to the same length, we opted for a multi-HDU
  output, where each BINTABLE contains the same number of rows (NAXIS2).

- CDF-FITS   	file format version (20 currently)
- CDF2FITS      software version ID (the CVS id)
- DATE		when the file was written

- ZVARnnn	the original zVar number (>=1) from the CDF file
		(in each relevant HDU)

- VATTRnnn	a very loose list of all the info for the variable attributes 
		(in each relevant HDU)

- GATTRnnn 	a very loose list of all the info for the global var's
		(only in the pHDU)
