Added alert dialog. Fixed image rotation EXIT data being discarded.

src/web/alerts.js

@@ -0,0 +1,20 @@
+'use strict';
+
+const { addAlert, removeAlert } = require('../alerts');
+
+async function addAlertApi(req, res) {
+	const alert = await addAlert(req.body, req.session.user);
+
+	res.send(alert);
+}
+
+async function removeAlertApi(req, res) {
+	await removeAlert(req.params.alertId);
+
+	res.status(204).send();
+}
+
+module.exports = {
+	addAlert: addAlertApi,
+	removeAlert: removeAlertApi,
+};