SPARK-1209 [CORE] SparkHadoop{MapRed,MapReduce}Util should not use package org.apache.hadoop

(This is just a look at what completely moving the classes would look like. I know Patrick flagged that as maybe not OK, although, it's private?)

Author: Sean Owen <sowen@cloudera.com>

Closes #2814 from srowen/SPARK-1209 and squashes the following commits:

ead1115 [Sean Owen] Disable MIMA warnings resulting from moving the class -- this was also part of the PairRDDFunctions type hierarchy though?
2d42c1d [Sean Owen] Move SparkHadoopMapRedUtil / SparkHadoopMapReduceUtil from org.apache.hadoop to org.apache.spark