Simplify SurfaceManagerGui, remove desctructor

src/Surfaces/SurfaceManagerGui.cpp

@@ -11,11 +11,6 @@ SurfaceManagerGui::SurfaceManagerGui(){
 	_cmdManager = 0;
 }
 
-SurfaceManagerGui::~SurfaceManagerGui(){
-	surfaceManager = 0;
-	_cmdManager = 0;
-}
-
 void SurfaceManagerGui::draw(){
 	if(surfaceManager == 0){
 		return;

src/Surfaces/SurfaceManagerGui.h

@@ -26,7 +26,6 @@ class SurfaceManagerGui {
 	
     public:
 		SurfaceManagerGui();
-		~SurfaceManagerGui();
 
 		void draw();
 		void mousePressed(ofMouseEventArgs & args);