Major Description
As per discussions in Hackathon, we have extracted interface out of HTable and named it as HTableInterface. This will make unit testing client code easier and simplify client API.
It opens other possibilities such as creating a HTable that does not do any RPC calls, MockHTable etc.
HTablePool still returns HTable instances. But we haxxve added a setter method for HTableInterfaceFactory on it. Thus developers can write their own HTableInterfaceFactory impl to return their own HTableInterface implementation.
I have assigned this issue to 0.21 but you may consider it to move it to 0.20 if possible.