How to update a tileset from 3.2 to 3.3

To update a tileset from 3.2 to 3.3 you must add some new graphics and update the file format strings.
==The .tilespec file==
* Set format of .tilespec file to options = "+Freeciv-3.3-tilespec" in final freeciv-3.3.
* Current development version uses options = "+Freeciv-tilespec-3.2-Devel-2022-Jun-21"
==The .spec files==
* Set format of all .spec files to options = "+Freeciv-3.3-spec" in final freeciv-3.3.
* Current development version uses options = "+Freeciv-spec-3.3-Devel-2023.Apr.05"