Make stamps part of the tileSet file

Nobody has claimed this yet.

Currently, stamps are saved in a .stamps file inside the Tile config folder. This approach has many limitations:

1. You cannot easily distribute the stamps for other persons of the team who only edit maps.
2. The stamp files even have absolute paths to the tileSet, so if you need to move the tileSet to some other folder, the stamps might break

So, IMHO, the best approach to stamps would be:

1. Make the stamps part of the tileSet (.tsx) file, since they only make sense with the respective tileSet
2. Allow each stamp variation to have their own name
3. Add a flag to select wether a stamp is enforceable or not. IOW, when the "enforceable" flag is enabled, individual tiles of the stamp cannot be used separately, since they form a single object: Selecting one tile of the stamp on the tileset will always automatically select all the tiles of the stamp. OTOH, when the "enforceable" flag is disabled, any of the stamp files can be freely selected on the tileSet. The "enforceable" flag also wouldn't allow the stamps to be partially overwritten on the map.
4. Allow Stamps to easily use transformed tiles: flipped and rotated

Start by examining how stamps are currently stored in the .stamps file inside the Tile config folder, then compare that representation with the .tsx tileSet file. The work is done when stamps are embedded in the tileSet, support named variations, enforceable behavior, and transformed tiles without relying on absolute paths.

Written by the indexing model from the issue text.