R1:a9fc343d9eda

Phriction - start the move towards transactions and an editor

Summary:
This implements as little as possible to stick a working transactions + editor codepath in the basic create / edit flow. Aside from the transaction tables, this also required adding a mailKey to a phrictionDocument.

Future work would include adding more transactions types for things like "move" and all the pertinent support. Even future work is to add things like policies which will work easily in the transaction framework. Ref T4029.