Phoenix 180

First revision for review.  There are some open points here.  Still no test case added to consume the stats.  Will do the performance test once the system is available with me.
Should be a builder.steTableNameBytes too, as schemaName and tableName are separate - see other calls on MetaDataEndpointImpl.

We should also add a startRow/stopRow so we can do a partial update of stats. See note in protobuf def of stats request.