- Fixed a bug caused by a mismatch between the actual and expected indexes of null/non-null option type members in AvroOptionUnionIO.
- Fixed a bug in AvroOptionUnionIO.asGenericHelper which previously returned the Unit value (which the Java reference serializer does not understand).  In those cases, this method now returns null.
- Updated AvroRecordIOSpec to verify the correctness of the above.
- Removed sub-project specific version numbers.
- Incremented the version patch number, project-wide.
Merge remote-tracking branch 'refs/remotes/github/master'