New in 1.0:

* The order of the keywords in the FITS header of the created mosaic
  file follows DICB recommendations.


New in 0.5.2:

* In case of a pipeline processed input file use ESO.PRO.CATG as
  additional criterium for selecting the second input file.


New in 0.3.3:

* Builds mosaic header from the master and slave frames.


New in 0.3.1:

* Fsmosaic now returns error codes to indicate the reason of
  failure (see create_mosaic.h for their definition).

* The second file needed for merging not searched in the current
  working directory, but in the same directory as the input file
  is located.


New in 0.3:

* When creating a mosaic the prescan area of the master and the
  overscan area of the slave are removed from the images before
  merging if they are present. This assumes that the contents of the
  YGAP keyword refers to the physical distance between the 2 CCDs
  measured in microns.

* fsmosaic replaces the FITS keywords ESO.DPR.* by the keyword
  ESO.PRO.CATG and assigns the value FORS2_MERGED_IMAGE to it.

* If an input file is passed to fsmosaic which contains already a
  FORS2 mosaic generated by fsmosaic the program prints an error
  message and stops. If this is not desirable the command line
  option '-p' or '--permissive' may be used. In this case the
  program copies the input file to the output file (as requested by
  Mario Kiekebush) and exits with status 0.

  A FORS2 mosaic created by fsmosaic is recognized by the presence
  of the product tag FORS2_MERGED_IMAGE in the keyword ESO.PRO.CATG,
  that the number of chips is 2 and that the chip identifier strings
  of the FORS2 master and slave CCD are present in ESO.DET.CHIP1.ID
  and ESO.DET.CHIP2.ID.

  In case a mosaic is passed as input file that was not created by
  fsmosaic the program still stops indicating an error.