MatrixEffect now uses dynamically allocated memory.

include/effect_matrix.h

@@ -30,9 +30,11 @@ public:
 
 class MatrixEffect : public Effect {
 private:
-    MatrixEffectColumn columns[LED_WIDTH];
+    MatrixEffectColumn* _columns;
 public:
     boolean can_be_shown_with_clock();
+    void start();
+    void stop();
     MatrixEffect();
     void loop();
 };