Update example to use `Settings` singleton

Add different way of entering fullscreen. Store -f in Settings and use `ofSetFullscreen()` during `ofApp::setup()`

example/src/main.cpp

@@ -2,6 +2,7 @@
 #include "ofApp.h"
 #include <string>
 #include <vector>
+#include "Settings.h"
 
 int main(int argc, char * argv[]){
 	bool fullscreen = false;
@@ -13,12 +14,9 @@ int main(int argc, char * argv[]){
 			break;
 		}
 	}
+	
+	Settings::instance()->setFullscreen(fullscreen);
 
-	if(fullscreen){
+	ofSetupOpenGL(800, 450, OF_WINDOW);
-		ofSetupOpenGL(800, 450, OF_FULLSCREEN);
-	}else{
-		ofSetupOpenGL(800, 450, OF_WINDOW);
-	}
-
 	ofRunApp(new ofApp());
 }

example/src/ofApp.cpp

@@ -19,6 +19,8 @@ void ofApp::setup(){
 
 	// The info layer is hidden by default, press <i> to toggle
 	// piMapper.showInfo();
+	
+	ofSetFullscreen(Settings::instance()->getFullscreen());
 }
 
 void ofApp::draw(){

example/src/ofApp.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "ofMain.h"
+#include "Settings.h"
 #include "ofxPiMapper.h"
 #include "CustomSource.h"
 #include "CrossSource.h"