New attack function for single character in characters.h, need implementation (example in shade.h)

src/characters.h

@@ -34,6 +34,12 @@ public:
         virtual result move_or_attack(const direction dir,
                                       const position_list &available_positions,
                                       character_list &chlist);
+
+        virtual result attack(const direction dir, character *ch) = 0;
+        virtual result move_or_attack(const direction dir,
+                                      const position_list &available_positions,
+                                      character *ch);
+
         virtual void apply(direction &dir,
                            potion_list &potions);
         virtual result get_hit(const enum race &race, const int atk,