Update copy constructors to be consistent, even when nothing needs to be copied in that class.
Track a version number for the generated group.
Persist generated storage format descriptors.
Add conversion for data as well as meta-data.
Add format for Protobuf in Persistit.
Add unit test and IT tests.
Update copy constructor.
Per review comments, save generated format directly in Storage, rather than separately where it can get out of sync.
Do encode DATE and DATETIME as strings.
Revert file that didn't need to change at all.
Update test results for datetime fields.
merge MMcM: Protobuf storage format

Merge pull request #1021 from MMcM/sql-layer/storage-format-protobuf
https://github.com/FoundationDB/sql-layer/pull/1021