RFC: MongoDB Migrations

[dealproc]

One of the changes with the last RC release mentions that users of this library are on their own to migrate from one RC to another, as the structure of the project changed dramatically.

My thinking is that we may want to provide some sort of a migration strategy, post 1.0.0, so that as we need to roll to 1.1, 1.2, and eventually 2.0 and beyond, folks can easily upgrade their projects with limited concern for our decisions.