Coprocessor Endpoints

[Jason Rutherglen]

I'm taking a look at TestCoprocessorEndpoint for example, in trying to
figure out how the Coprocessor RPC works.  I think
HTable.coprocessorProxy should be used?  Which will return an
interface that when called performs the network marshaling etc.  The
purpose of the row byte[] in coprocessorProxy is to find the correct
region to make the call to?