added support for "prevent next [number] damage" to player/creature.

projects/mtg/include/Damage.h

@@ -23,12 +23,14 @@ class Damageable:public Targetable {
   int life;
   int poisonCount;
   int damageCount;
+  int preventable;
   int type_as_damageable;
   Damageable(int _life){life=_life;};
   int getLife(){return life;};
   virtual int dealDamage(int damage){life-=damage;return life;};
   virtual int afterDamage(){return 0;}
   virtual int poisoned(){return 0;}
+  virtual int prevented(){return 0;}
   virtual JQuad * getIcon(){return NULL;};
 };