Add CityMania savegame data (a bit broken for now)

source.list

@@ -1193,6 +1193,8 @@ sound/null_s.cpp
 thread.h
 
 # CityMania
+citymania/cm_bitstream.hpp
+citymania/cm_bitstream.cpp
 citymania/cm_console_cmds.hpp
 citymania/cm_console_cmds.cpp
 citymania/cm_event.hpp
@@ -1203,5 +1205,8 @@ citymania/cm_game.cpp
 citymania/cm_main.hpp
 citymania/cm_main.cpp
 citymania/cm_type.hpp
+citymania/cm_saveload.hpp
+citymania/cm_saveload.cpp
+citymania/cm_settings.hpp
 citymania/extensions/cmext_town.hpp
 citymania/extensions/cmext_company.hpp