add SYS_MainLoop to rest of examples

Author: WinterMute

devices/usbkeyboard/basic_stdin/source/basic_stdin.c

@@ -93,7 +93,7 @@ int main(int argc, char **argv)
 
 		// Wait for the next frame
 		VIDEO_WaitVSync();
-	} while (!quitapp);
+	} while (!quitapp && SYS_MainLoop());
 
 	return 0;
 }

filesystem/directory/isfs/source/main.c

@@ -364,7 +364,7 @@ int main(int argc, char** argv) {
     RenderDirectoryListing(&parent, selected_index, 20);
 
     // Main Loop (Watchin for button presses).
-    while(true) {
+    while(SYS_MainLoop()) {
         // Scan WPAD
         WPAD_ScanPads();
         s32 pressed = WPAD_ButtonsDown(WPAD_CHAN_0);

graphics/gx/romfont/source/romfont.c

@@ -262,7 +262,7 @@ int main(int argc, char **argv)
     setup_font();
     setup_viewport();
 
-    while (true) {
+    while (SYS_MainLoop()) {
         WPAD_ScanPads();
 
         u32 pressed = WPAD_ButtonsDown(0);

threading/source/main.c

@@ -50,7 +50,7 @@ static void* main_thread(void* arg) {
 
     // Main Thread Loop
     bool quit=false;
-    while(!quit) {
+    while(!quit && SYS_MainLoop()) {
         // Scan WPAD
         WPAD_ScanPads();
         s32 pressed = WPAD_ButtonsDown(WPAD_CHAN_0);