HCat's HCatReader and HCatWriter interfaces expose Hadoop classes Configuration and InputSplit, as well as HCatInputSplit. This exposes users to changes over Hadoop or HCatalog versions. It also makes it harder to some day move this interface to use WebHCat, which we'd like to do. The eventual goal is for this interface to not require any other jars (no Hadoop, Hive, etc.) As a first step to this the references to Hadoop and HCat classes in the interface should be hidden.