fixed:

1. potions being walked over
2. spawning on stairs
3. enemies walking under players
4. merchants not being aggresive
5. potions losing effect when sending pass signal (cleared by player::start_turn())’

src/cursor.cc

@@ -30,7 +30,7 @@ void cursor::show() const {
 }
 
 void cursor::clear() const {
-        ::clear();
+        //        ::clear();
 }
 
 void cursor::print_char(const position &pos, const char ch,