Nuxeo document schema Avro converter

Some R&D must be done to know:

• If we can generate the Avro schema corresponding to a Document type.
• If using this schema we can encode/decode document

possible gain:

• ultra compact encoding for client protocol
• import format of choice for importer, we can expect that data is validated before running the import.
• export format reusable outside of Nuxeo

There is an avro file format that can be used as input of the Nuxeo stream importer.
This file format can be turn to valid JSON using avro tools.