window management fixes (fixes #426)

app/lib/index.ts

@@ -26,6 +26,10 @@ app.on('activate', () => {
     }
 })
 
+app.on('window-all-closed', () => {
+    app.quit()
+})
+
 process.on('uncaughtException' as any, err => {
     console.log(err)
     application.broadcast('uncaughtException', err)