Sets or gets the value of the given battle flag.
Battle flags are the flags found in the battle/*.conf files and is also used in Lupus' variable rates script.

Example(s):

//will set the base experience rate to 20x (2000%)
setBattleFlag "base_exp_rate",2000;

//will return the value of the base experience rate (when used after the above example, it would return 2000).
getBattleFlag "base_exp_rate";