[daip] UVMOD HLP file is wrong about model type

[Eric Greisen]

Michael Bietenholz writes:
 >    If I put CTYPE = 5, which is supposed to get an optically-thin
 > sphere, I instead get a "Exp" (that is what the HI entries claim,
 > and UV-plot looks like and "exp" also).  To actually get a SPHE
 > model, I think you need CTYPE = 4.
 > 
 > (31DEC07, MNJ Nov 22)

The HELP file says

   CTYPE......Type of each source: 1 Gaussian, 2 solid disk, 3 solid
              rectangle, 4 optically thin sphere, 5 exponential
              otherwise point

Which agrees with your finding.

The explain file seems to be wrong - will deal with it.

Eric