Bug Fixes for v 0.3.0

There are several fixes coming in this PR:

1) Transactions are not being released at the end. 
I'm not positive why this is, but I do know that these callbacks do not execute unless run in a twisted run loop. Perhaps someone else can figure out why or figure out a clever way around this.

2) Contracts are missing Escrow information.

3) Notaries added to your trusted notary list have a None check issue.
Oh, finally. This line was bringing tears to my eyes.