Support for pause/resume of game rendering loop (#476)

* added pause/resume

* don't override displaymode in game engine

* avoid setting light sensing display mode

docs/reference/game.md

@@ -30,6 +30,8 @@ game.setScore(0);
 ```cards
 game.startCountdown(10000);
 game.gameOver();
+game.pause();
+game.resume();
 ```
 
 ### See also
@@ -38,4 +40,5 @@ game.gameOver();
 [ifOnEdgeBounce](/reference/game/if-on-edge-bounce), [get](/reference/game/get), [set](/reference/game/set),
 [change](/reference/game/change), [isTouching](/reference/game/touching) [isTouchingEdge](/reference/game/touching-edge),
 [addScore](/reference/game/change-score-by), [score](/reference/game/score), [setScore](/reference/game/set-score),
-[startCountdown](/reference/game/start-countdown), [gameOver](/reference/game/game-over)
+[startCountdown](/reference/game/start-countdown), [gameOver](/reference/game/game-over),
+[pause](/reference/game/pause), [resume](/reference/game/resume)

docs/reference/game/pause.md

@@ -0,0 +1,11 @@
+# Pause
+
+Pauses the game rendering engine to allow other animations on the screen.
+
+```sig
+game.pause()
+```
+
+### See Also
+
+[resume](/reference/game/resume)

docs/reference/game/resume.md

@@ -0,0 +1,11 @@
+# Resume
+
+Resumes the game rendering engine after a pause.
+
+```sig
+game.resume()
+```
+
+### See Also
+
+[pause](/reference/game/pause)