[Java API] Fix equality checks on PojoTypeInfo
[APIs] Add ExecutionConfig
[FLINK-1325] [Java API] Add Java ClosureCleaner

This closes #269
[FLINK-1325] [Java API] Minor cleanups on the ClosureCleaner
Fix invalid type hierarchy creation by Pojo logic
[FLINK-610] Replace Avro by Kryo as the GenericType serializer

The performance of data-intensive jobs using Kryo is probably going to be slow.
[FLINK-1333] Fixed getter/setter recognition for POJOs