Log Message:
geography/gama: Update to 2.13

Changes in release 2.13 (2021-01-15)

* [new program gama-local-gkf2yaml]

* Command line programs gama-local, gama-local-yaml2gkf and
  gama-local-gkf2yaml can now read input data from standard input.

* New exlicit parameter --input-xml in gama-local (previously input
  file was the first parameter)

* [bug fixes and minor improvements]