Adaptation of the Qgis Model Baker plugin v6.3.2.

From Qgis Model Baker's about:
-------------------------------------------------------------------------------
This project is open source under the terms of the GPLv2 or later and
the source code can be found on https://github.com/opengisch/QgisModelBaker.

This plugin is developed by OPENGIS.ch in collaboration with SwissTierras
Colombia.
-------------------------------------------------------------------------------