app.use(.......); for middleware.....uses next....goes down the ladder until you stop it
app.use(function(err, req, res, next){ } called cross cutting
app.use('/', application_controller);
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: (app.get('env') === 'development') ? err : {}
});
});