add basic notification system

notify.html

@@ -0,0 +1,5 @@
+<script>
+  require('electron').ipcRenderer.on('notification', (ev, { title, body }) => {
+    new Notification(title, { body });
+  });
+</script>

notify.js

@@ -0,0 +1,29 @@
+const { app, BrowserWindow } = require('electron');
+const isDev = require('electron-is-dev');
+const { resolve } = require('path');
+
+let win;
+
+// the hack of all hacks
+// electron doesn't have a built in notification thing,
+// so we launch a window on which we can use the
+// HTML5 `Notification` API :'(
+
+app.on('ready', () => {
+  const win_ = new BrowserWindow({
+    show: false
+  });
+  const url = 'file://' + resolve(
+    isDev ? __dirname : app.getAppPath(),
+    'notify.html'
+  );
+  win_.loadURL(url);
+  win = win_;
+});
+
+module.exports = function notify (title, body) {
+  if (win) {
+    win.webContents.send('notification', { title, body });
+  }
+  // TODO: buffer ?
+};