add date and month as global script variables so that season based events can be added to the game

[meszaros-lajos-gyorgy]

Idea: replace apples with pumpkins and apple pies with pumpkin pies on halloween:

// apple 

ON INIT {
  // ...
  IF (^#realtime_month == 10) {
    IF (^#realtime_day == 31) {
      // replace texture, name and size to resamble a pumpkin
    }
  }
}

[meszaros-lajos-gyorgy]

Other system variables can be found here: https://wiki.arx-libertatis.org/Script:Variables#System_variables

[meszaros-lajos-gyorgy]

source of the solution: https://stackoverflow.com/a/15958113/1806628