GEOMESA-164 

adding geomesa pages to geoserver - accumulo stats, hdfs stats, hdfs config, initiate m/r jobs
Rather than scanning the METADATA table, can you use the ```Command```s in ```org.apache.accumulo.core.util.shell.commands```?  There's a ```GetSplitsCommand```, a ```DUCommand```, etc.  This keeps us isolated from the schema and structure of the METADATA table.