Remove hive operators

In order to make the Shark operator cleaner, this change replaces the Hive Operator with the XXXDesc as the type parameters for Shark Operators, now the Shark Operator creates its own output object inspectors per XXXDesc directly. This change also will benefits the codegen for the further update.

BTW: Compared to the https://github.com/amplab/shark/pull/162, I removed the Join Filter bug fixing.

Thanks,
Cheng Hao