Refactor Kryo serializer support to use chill/chill-java

This pull request replaces Spark's currently custom `KryoSerializer` with one based on `chill` and `chill-java`. More details can be found here: https://github.com/mesos/spark/pull/590

I tested this with `java.util.Arrays.asList` and all seems to work well now that we have chill-java in place. Hopefully this is now in a state to be merged.

@rxin @mateiz @johnynek @sritchie