NAME:
  rdwfc3
 PURPOSE:   (one line only)
  Read a HST WFC3 image with an associated mask and select header information
 DESCRIPTION:
 CATEGORY:
  File I/O
 CALLING SEQUENCE:
  rdwfc3,root,det,data
 INPUTS:
  root - String with the root of the file name (preceeds '_')
  det  - which detector 1 = UVIS1 and 2 = UVIS2
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  DDIR - Directory where data can be found
  TYPE - Data file type (flt or flc) to read, default='flc'
  SATUR - saturation level for detectory.  Default=80000.0
            This is used to build a mask if not is found where all pixels
            above this level are automatically set to bad.
 OUTPUTS:
  data - anonymous structure with all the collected information.
            On failure, data=!null.  The following tags are defined.
      fnim:  Full file name with path for the image file read
      fnmsk: Full file name with path for the mask file read
      image: The image
      mask:  The mask, same size as the image
      maskhdr: The header from the mask image
      nx:    Width of the image in pixels
      ny:    Height of the image in pixels
      date:  UT Date at start of exposure (string)
      time:  UT Time at start of exposures (string)
      exptime: Exposure time (seconds)
      filter: Name of the filter used
      astinfo:  anonymous structure with the wcs solution from the header
      epoch: Mid-time of exposure in decimal years
      jdmid: UT JD of the mid-time of the exposure

 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  2020/06/23, Written by Marc W. Buie, Southwest Research Institute.
                Generalized from previous prototype versions.