remove outcommented code
remove unused code

level_.child("player") is always false so we always call
level_to_gamestate.

(compability handling is done in savegame.cpp)
make saved_game::carryoves_sides(_start) private
using a bool to remember whether we expanded carryover

instead of having 2 objects from which exactly one is empty and then
check by using empty().
move scenario hash generation to expand_scenario
use expand_scenario function in create_engine.cpp
fix random generated mp maps.

fix https://gna.org/bugs/?22410