renamed display to output

src/cc3k.h

@@ -2,7 +2,7 @@
 #define __CC3K_H__
 
 #include "input.h"
-#include "display.h"
+#include "output.h"
 #include "game.h"
 #include "menu.h"
 #include "result.h"
@@ -11,7 +11,7 @@ class CC3K final {
 private:
         const feature enabled_features;
         input *in;
-        display *out;
+        output *out;
         RNG *rng;
 
         game_result gresult;
@@ -19,7 +19,7 @@ private:
         std::unique_ptr<menu> curr_menu;
 public:
         CC3K(const feature enabled_features,
-             input *in, display *out, RNG *rng);
+             input *in, output *out, RNG *rng);
         game_status run();
 };