Start transitioning :keycode to :key so it is consistent with :button

src/play_clj/core.clj

@@ -133,7 +133,7 @@ via the screen map.
     (defscreen my-screen
       :on-key-down ; a key was pressed
       (fn [screen entities]
-        (println (:keycode screen)) ; the code of the key (see key-code)
+        (println (:key screen)) ; the code of the key (see key-code)
         entities)
       :on-key-typed ; a key was typed
       (fn [screen entities]
@@ -141,7 +141,7 @@ via the screen map.
         entities)
       :on-key-up ; a key was released
       (fn [screen entities]
-        (println (:keycode screen)) ; the code of the key (see key-code)
+        (println (:key screen)) ; the code of the key (see key-code)
         entities)
       :on-mouse-moved ; the mouse was moved without pressing any buttons
       (fn [screen entities]

src/play_clj/core_listeners.clj

@@ -8,13 +8,13 @@
    execute-fn!]
   (reify InputProcessor
     (keyDown [this k]
-      (execute-fn! on-key-down :keycode k)
+      (execute-fn! on-key-down :key k :keycode k)
       false)
     (keyTyped [this c]
       (execute-fn! on-key-typed :character c)
       false)
     (keyUp [this k]
-      (execute-fn! on-key-up :keycode k)
+      (execute-fn! on-key-up :key k :keycode k)
       false)
     (mouseMoved [this sx sy]
       (execute-fn! on-mouse-moved :input-x sx :input-y sy)