GEOMESA-159 Eliminate redundant copies of a value in the SimpleFeatureFilteringIterator
GEOMESA-288 Export to stdOut

Exporting to stdOut is now achievable by giving the export command the -s or --stdout flag. Additionally, the list and describe commands now have a -q or --quiet option for better piping of their outputs.
GEOMESA-278 removing unused action page
GEOMESA-291 adding more data store params to GeoServer interface
GEOMESA-268 updating menu icons in geoserver
Merge remote-tracking branch 'lt/accumulo1.5.x/1.x' into stealth
GEOMESA-280 fixing NPE for non-existing props
Merge remote-tracking branch 'lt/accumulo1.5.x/1.x' into stealth