Hordes nolight

Hordes.
 - more zombie groups, but less monsters count in it.
 - crossovermap signals and hordes moving
 - information about horde size and speed on map
 - more fast debug
 - tracks
 - removed light signals 
Instead of aging the tracks, we should just account for intervening weather when the monster tries to track the player.  The weather is available via game::weather_log, which is a std::map<int, weather_segment>.  The int is the turn when that weather condition started, and weather_segment has the temperature and weather type that was occurring during that time period.  You can look at weather::fill_funnels() for an example of historical weather data being used.

The reason for this is that different monsters might be able to track based on different things, for example a NPC or intelligent robot might be able to track based on traces that weather won't wash away as rapidly, while wolves will be able to track based on scent for a long time.  There might even be a creature that has a supernatural ability to track the player, and just succeeds dispute any intervening weather conditions.