Report correct server hosting a table split for assignment to for MR Jobs

Currently we return a null String array to the MR framework to use a random node for MR job assignment.

class: org.apache.hadoop.hbase.mapred.tableSplit
function getLocations()

We should be able to query the meta now for the current host name of the server hosting the region in question.
This will help with scaling as there will be less cross server communication removing bandwidth as a bottleneck.

The side effect of fixing this will help from overloading region servers with lots of MR clients all pulling from the same region server while theres work local for them to do.