This commit does not affect the processing.

Some final touches were made to the pipeline to make it easier and
more stable for reproduction. The most important changes are:

 - The configuration files now have the specific version of Gnuastro
   in them so the pipeline doesn't run with any other version.

 - A README file was added to explain how to run the pipeline and also
   the dependencies.

 - Since the `flock' program might not be available on some systems, a
   Perl script was put in `reproduce/scripts/flock' so people can use
   it instead.

 - Some corrections were made in the downloaded file names.

 - Until now, the pipeline used a separate version of Gnuastro for its
   Table program which could write output into a FITS table (version
   0.2.51-bc56 which is used in the pipeline can't do that). But the
   format of the output is irrelevant, for the purpose here, the
   contents are important. So this step was removed and the final
   tarball output of the pipeline is now fully reproducible with the
   single 0.2.51-bc56 version of Gnuastro.

 - The final tarball is placed in the `reproduce/output' directory,
   because it may be necessary later (when the intermediate files are
   deleted).