A simple Python ORM for CouchDB and Couchbase Sync Gateway.

Fam adds a type and namespace to each document:
* type - A lower case string derived from the class name
* namespace - An opaque string to help avoid class name clashes and
  allow versioning of classes

And uses them to provide:
- A class to bind methods to documents
- Automatic generation of design documents for relationships between classes
- Lookup of related documents
- Validation of documents
- Document life-cycle callbacks for creation, updates and deletion
- Optional cascading deletion through relationships