NAME:
  astanal
 PURPOSE:   (one line only)
  Analyze and provide summary plots and averages for one night of astrometry
 DESCRIPTION:
 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  astanal,fnfit,fncenter
 INPUTS:
  fnfit - Fit coefficient file to read, default is fitcoeff.dat
  fncenter - Centers file to read, default is centers.dat
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  PATH      - Location of the images, default is the current directory.
  KEYFILE   - header keyword correspondence file (see loadkeys.pro)
  NODISPLAY - Flag, if set suppresses all plots
  SAVEMEAN  - Flag, if set will cause the program to save the filter by
               filter averages of the coefficients into a file named
               forcecoeff.dat
  SILENT    - Flag, if set suppresses all printed output
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
  CONVERGED - Output flag, if set then the CONST term of all of the fits
                never exceeds 1 milli-arcsecond
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Southwest Research Institute, 2009/12/30
  2010/11/22, MWB, added PATH keyword
  2011/02/21, MWB, enhancement to completely skip fitcoeff.dat entries
                     where the files cannot be found.