Unverified new user can create unassociated asks/offers.

[solebared]

From @grenewode: after signing up, but before verifying account, you are about to create anon asks/offers. This could confuse users who might expect to have asks and offers created linked to their new account at this point.

Two thoughts:

1. Do we need to make the 'please verify' message more prominent
2. Can we cookie the session in which a new user registers so that we can recognize the situation above and inform the user accordingly?