
Region APIs

Region table is a FITS table

- load region data from FITS table
- save region data to FITS table

/* find region which overlaps c at given depth (-1 : max depth) */
SkyRegion *SkyFindPoint (SkyRegion *db, SkyCoord c, int depth);

/* find regions at all levels which overlap c */
SkyRegion **SkyFindLevels (SkyRegion *db, SkyCoord c, int *Nregion);

/* find regions contained within rectangular region  c1 - c2 */
SkyRegion **SkyFindArea (SkyRegion *db, SkyCoord c1, SkyCoord c2, *nlist);

- I have created table generation functions which construct a
  collection of table entries starting with the full sky and iterating
  down N levels.  The function also fills out the names at the
  appropriate levels.  This is currently ok up to level 6, but runs
  out of memory at level 7.  This should not be the case, so I suspect
  I'm not free'ing some memory.  

- I need to create a function to take the GSC table list and construct
  a set of SkyRegions that match the layout, starting with the full
  sky and iterating down to and past the GSC tables.  

