Verification process for current users who try to bid through the sign in and pledge form

Please review and comment below on any changes.

![confirm-oldbidishigher](https://f.cloud.github.com/assets/4898672/1728622/4260b8e6-62b2-11e3-9fcb-c12d36eb63cb.png)
![confirm-samerates](https://f.cloud.github.com/assets/4898672/1728623/42625be2-62b2-11e3-9549-61ca3eed5d96.png)