The texture array used by WS30 requires that all component textures be the same size and format. This commit adds an alpha channel to those png file used as primary textures in materials.xml files which did not have one.
Replace textures that aren't GPL license-compatible. From https://github.com/gilbertohasnofb/new-regional-textures commit 581fb2795a4e068f807ad8c45558eddcf4c0b69c As requested by Gilberto AGOSTINHO.