[FL-1475] iButton emulate shortcat (#535)

* ibutton: run emulation when launched with argument
* app-loader: set NULL context when starting application from menu
* ibutton: change p to argc
* ibutton: fix load key data from file
* ibutton: fix memory leak

applications/ibutton/ibutton.cpp

@@ -3,7 +3,7 @@
 // app enter function
 extern "C" int32_t app_ibutton(void* p) {
     iButtonApp* app = new iButtonApp();
-    app->run();
+    app->run(p);
     delete app;
 
     return 255;