Remove useless codes.
Add validator.
Add express session.
Add connect-flash.
Add text.
Require session, connect-flash.
Add function to check register information.
Add connect mongo
Add settings.js to config DB.
Add db.js to get db instance.
Config session.
Add html for error message
Config session and cookie.
Now we can display error or success message.
Now we can validate register form and display message.