Advanced refitting

[George]

It would be good to have more variants for refitting. With advanced refitting it should be possible not only to change the cargo type (and graphics for this cargo type), but also all the personal vehicle characteristics (like speed, capacity, cargo type, but not the power, running cost and other type's characteristics) and graphics for existing cargo.

[SHADOW-XIII]

indeed but first of all it would be good to have possibility to refit trains to mail and/or to passenger (only one of those is on the list now)