application: More code style cleanup and reorganization

src/main.c

@@ -33,6 +33,8 @@ main (int   argc,
   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
   textdomain (GETTEXT_PACKAGE);
 
+  g_set_application_name ("Calendar");
+
   app = gcal_application_new ();
 
   return g_application_run (G_APPLICATION (app), argc, argv);