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)
may be
``` python
@app.route('/user/verify/<token>/')
@auth.login_required
def user_verify(token):
...
  user_db = auth.current_user_db()
  if user_db.token != token:
    flask.flash('Invalid token, please try again ' ' or something like that')
    return flask.redirect(flask.url_for('profile'))
....
```