Revert "[ADAM-237] Migrate to Chill serialization libraries."

This reverts commit 39821152352e6647a244d1df24facafa53aa6923.

The migration to the Chill library used the Avro container format instead of the binary format. That meant that each Avro object was wrapped in container data (that included the schema, block markers, etc) causing much of the memory headaches we've been dealing with.

The Chill library does have simple way to move to the binary format (`.asBinary`) but the implementation is not nearly as efficient as the simple serializer class we already had (which reuses classes and buffers).

The Chill library is great -- clean, succinct code for serialization interoperability -- but it doesn't buy us anything to use it.
is bumping this backward intended / ok?