Added email verification for users

The verification email is sent if needed when profile is updated (either when the email is changed from the previous time or it was an old account and didn't have the token value)

You can test it here: http://verify.gae-init.appspot.com/profile/

![screen shot 2014-08-14 at 19 46 25](https://cloud.githubusercontent.com/assets/125676/3924464/a9cb5d1e-23dd-11e4-9c63-54d00363f42c.png)
I'm using the `user_db.token =` twice.. during the verification link to generate a brand new thing so only the latest one will work.. and then when actually verifying.. so that token if you click on it again it will be expired..